Fully-automatic selective soldering system and method for PCB

Abstract

Provided in the present invention are a fully-automatic selective soldering system and method for a PCB. The fully-automatic selective soldering system comprises the following components arranged in sequence: a soldering flux spray-coating mechanism; a first conveying mechanism, which is used for conveying a PCB to a spray-coating station of the soldering flux spray-coating mechanism; a preheating mechanism, which is used for preheating the PCB after spray-coating, wherein a third conveying mechanism is provided inside the preheating mechanism; a second conveying mechanism, which is used for conveying the preheated PCB to a position above a rotary soldering mechanism; and the rotary soldering mechanism, which is used for performing soldering of the preheated PCB. The soldering flux spray-coating mechanism is located below the first conveying mechanism; the rotary soldering mechanism is located below the second conveying mechanism; and the first conveying mechanism and the second conveying mechanism are respectively connected to two ends of the third conveying mechanism. Such a configuration simplifies the structure of a conveying portion, making the overall structure of an apparatus more compact, and also significantly shortens the conveying path of a PCB between processes, thereby significantly improving working efficiency.

Description

A fully automatic selective soldering system and method for PCB boards Technical Field

[0001] [Corrected 27.10.2023 according to Rule 91] The present invention relates to the technical field of soldering devices, and in particular to a fully automatic selective soldering system and method for PCB boards. Background Art

[0002] [Corrected 27.10.2023 according to Regulation 91] In automated production, soldering is an indispensable part of many electronic products and equipment, and the wave soldering process is widely used in circuit board assembly, such as integrated circuits, printed circuit boards, electronic components, automotive parts, etc. [0002.1] [Corrected 27.10.2023 according to Rule 91] Chinese invention application CN202210295535.0 discloses a wave soldering apparatus comprising: a body having a feed inlet and a discharge in communication; a transmission track mounted on the body, the transmission track being adapted to feed products to be soldered from the feed inlet to the discharge; a flux spray device, a preheating device, and a soldering device distributed within the body along a feeding direction of the transmission track; the transmission track comprising a first and second independent track, the first track being disposed opposite the flux spray device. However, the preheating track in the above scheme is relatively long and distant, not only occupying expensive factory space but also increasing the cost of subsequent track maintenance. [0002.2] [Corrected 27.10.2023 according to Rule 91] Chinese invention patent CN201611006043.6 discloses a desktop selective wave soldering machine, wherein a movable mounting frame is mounted on the upper end side of a fixed mounting base, the movable mounting frame is mounted on a movable support plate, and a tin pump assembly is mounted on the lower end side of the movable support plate of the fixed mounting base; the fixed mounting base is mounted on a Y-axis drive linear module, the driving end of the Y-axis drive linear module is mounted on a Z-axis drive linear module, and the movable mounting frame is mounted on an X-axis drive linear module; the tin pump assembly includes a tin pump mounting frame, a tin pot assembly, and a tin liquid pumping mechanism. The tin pot assembly includes a tin pot body, a tin pot cover plate, and an electric heating plate. The tin liquid pumping mechanism includes a housing base, a housing panel, a drive impeller, a drive shaft, a pumping drive motor, and a tin liquid nozzle; and the desktop selective wave soldering machine is equipped with a controller. However, due to the single tin pump assembly, it is difficult to meet the requirements of single-board multi-process soldering with different solder joint processes for the same product. [0002.3] [Corrected 27.10.2023 according to Rule 91] SUMMARY OF THE INVENTION Technical issues

[0003] [Corrected 27 October 2023, per Rule 91] The existing wave soldering process generally includes flux spraying, preheating, and soldering. However, existing equipment suffers from the following drawbacks: The circuit boards to be soldered require a lengthy process to move between each process station, which impacts overall soldering efficiency and reduces overall soldering time. Furthermore, the transport mechanisms between each process station are excessively long and poorly laid out, occupying expensive factory floor space and increasing future track maintenance costs. Furthermore, the excessively long transport mechanisms result in lower temperatures for preheated PCBs entering the soldering station, failing to meet soldering requirements and further impacting soldering quality. Furthermore, existing selective wave soldering machines can only provide one soldering process per weld, failing to simultaneously accommodate multiple soldering processes for the same product. Furthermore, they are bulky and lack integration.

[0004] [Corrected 27.10.2023 according to Rule 91] Therefore, it is necessary to design a fully automatic selective soldering system for PCB boards to solve the above problems.

[0005] [Corrected 27.10.2023 in accordance with Article 91] [Deleted]

[0006] [Corrected 27.10.2023 in accordance with Article 91] [Deleted] Technical Solutions

[0007] The object of the present invention is to provide a fully automatic selective soldering system for PCB boards with a compact structure, high soldering efficiency and stable soldering quality.

[0008] To achieve the above object, the present invention adopts the following technical solution: a fully automatic selective soldering system for PCB boards, which comprises

[0009] A flux spraying mechanism is used to spray flux onto the parts of the PCB to be soldered;

[0010] The first conveying mechanism is used to convey the PCB board to the spraying station of the flux spraying mechanism;

[0011] A preheating mechanism, used to preheat the PCB board after spraying, the preheating mechanism is a warehouse-type preheating mechanism with at least two layers, and the preheating mechanism is provided with a third conveying mechanism and a Z-axis module;

[0012] The second conveying mechanism is used to convey the preheated PCB board to the top of the rotary welding mechanism;

[0013] Rotary welding mechanism, used to weld the preheated PCB board;

[0014] The flux spraying mechanism is located below the first conveying mechanism, the rotary welding mechanism is located below the second conveying mechanism, and the first conveying mechanism and the second conveying mechanism are respectively connected to two ends of the third conveying mechanism.

[0015] As a further improved technical solution of the present invention, the preheating mechanism includes at least two stacked preheating units, each layer of the preheating unit is provided with the third conveying mechanism, and the Z-axis module is used to adjust the position of the preheating unit in the Z-axis direction to dock the first conveying mechanism with the third conveying mechanism.

[0016] As a further improved technical solution of the present invention, the preheating unit includes an upper preheater and a lower preheater, and a preheating chamber is formed between the upper preheater and the lower preheater.

[0017] As a further improved technical solution of the present invention, the upper preheater includes a metal shell and a hot air unit therein, and the lower preheater is a far-infrared lamp.

[0018] As a further improved technical solution of the present invention, each of the preheating units further includes a temperature controller.

[0019] As a further improved technical solution of the present invention, the first conveying mechanism includes a bracket, two first conveying rails arranged side by side, a first roller group or a first chain arranged on the first conveying rails, and a first conveying motor driving the first roller group or the first chain, and the PCB board moves under the drive of the two groups of first roller groups or the first chain.

[0020] As a further improved technical solution of the present invention, the first conveying mechanism also includes a width adjustment component, which includes a width adjustment screw rod, a width adjustment screw rod nut and a width adjustment motor. The width adjustment screw rod and the width adjustment screw rod nut drive one of the first conveying rails to approach or move away from the other first conveying rail.

[0021] As a further improved technical solution of the present invention, the first conveying mechanism also includes a height adjustment component, which includes a height adjustment screw, a height adjustment screw nut and a height adjustment motor. The height adjustment screw nut is fixedly connected to the bracket to adjust the height of the first conveying track and the first roller group or the first chain.

[0022] As a further improved technical solution of the present invention, the first conveying mechanism also includes positioning components respectively arranged on the two first conveying rails, each positioning component includes a positioning cylinder, an output rod, a support seat and a positioning plate connected in sequence, the positioning cylinder drives the positioning plate to move in a direction perpendicular to the PCB board, and the positioning plate cooperates with the first roller group or the first chain to clamp the PCB board.

[0023] As a further improved technical solution of the present invention, the rotary welding mechanism includes a base and a welding assembly, and the welding assembly includes two welding furnaces movably arranged on a main fixed plate.

[0024] As a further improved technical solution of the present invention, the rotary welding mechanism further includes a rotating assembly provided on the base for driving the welding assembly to rotate and a lifting assembly for driving the welding assembly to rise and fall.

[0025] As a further improved technical solution of the present invention, the rotary welding mechanism further includes an adjusting component, and the adjusting component includes a cam capable of adjusting the height difference between the two welding furnaces.

[0026] As a further improved technical solution of the present invention, the adjustment component is suitable for preventing the two welding furnaces from colliding with the PCB board during the rotation process.

[0027] As a further improved technical solution of the present invention, the cam is located on the rotating circumference of the welding furnace, and a fisheye bearing is provided at the bottom of the welding furnace. When one of the welding furnaces rotates to above the cam, the fisheye bearing cooperates with the cam to lift the welding furnace.

[0028] As a further improved technical solution of the present invention, the welding furnace includes a furnace body, a nozzle, an upper fixed plate for fixing the furnace body, a lower fixed plate, and a plurality of fixed rods connecting the upper fixed plate and the lower fixed plate, the upper fixed plate being arranged in the circumferential direction of the furnace body; the fixed rods are passed through the total fixed plate, the welding furnace can move up and down relative to the total fixed plate, a linear bearing is provided on the total fixed plate, and the lower surface of the upper fixed plate is provided with an axis fixing seat for mounting the fixed rods.

[0029] As a further improved technical solution of the present invention, the rotating assembly includes a fixed gear fixed on the base, a rotating bearing, a rotating shaft, a rotating motor fixed to the rotating shaft, and a movable gear driven by the rotating motor. The movable gear is engaged with the fixed gear to drive the rotating shaft and the welding assembly to rotate.

[0030] As a further improved technical solution of the present invention, the lifting assembly includes a rotating platform fixed to the rotating shaft, a lifting motor, a screw rod and a scissor arm arranged on the rotating platform, the scissor arm is arranged between the main fixed plate and the rotating platform, and the lifting motor drives the main fixed plate to rise and fall through the screw rod and the scissor arm.

[0031] As a further improved technical solution of the present invention, the rotary welding mechanism also includes a visual component, which is used for optical collection and detection of the PCB board and is arranged on the upper surface of the total fixed plate and located between the welding furnaces.

[0032] As a further improved technical solution of the present invention, the rotary welding mechanism further includes a laser temperature compensation component, which is arranged above the main fixed plate and close to the nozzle to heat and compensate the temperature of the PCB board.

[0033] As a further improved technical solution of the present invention, it further includes a moving mechanism, which is arranged below the rotary welding mechanism and is used to drive the rotary welding mechanism to move in the horizontal direction.

[0034] As a further improved technical solution of the present invention, an AOI inspection module is also included, which can directly check the yield of the solder joints after soldering is completed, and determine whether the PCB board needs to be re-soldered or moved out of the work station based on the results and an alarm is issued.

[0035] To achieve the above object, the present invention adopts the following technical solution: a fully automatic selective soldering method for PCB boards, which uses the above-mentioned fully automatic selective soldering system for PCB boards to operate the PCB boards, and the steps include:

[0036] S1: PCB feeding and transmission: The PCB is transported to the spraying station of the flux spraying mechanism through the first conveying mechanism;

[0037] S2: Use the vision module and electronic spray gun to spray the PCB accurately;

[0038] S3: Control the third conveying mechanism to dock with the first conveying mechanism through the Z-axis module, so that the sprayed PCB board can be placed in different layers of the preheating mechanism for preheating respectively;

[0039] S4: The preheated PCB board can be transported to the top of the rotary welding mechanism by docking the third conveying mechanism with the second conveying mechanism;

[0040] S5: The preheated PCB board is welded by the rotary welding mechanism. Beneficial effects

[0041] As can be seen from the above technical solutions, the fully automatic selective soldering system for PCB boards of the present invention arranges the flux spraying mechanism below the first conveying mechanism, the rotary soldering mechanism below the second conveying mechanism, and the first conveying mechanism and the second conveying mechanism are respectively docked with the ends of the third conveying mechanism, so that the conveying path of the PCB board is a straight line, and the spraying, preheating and soldering processes are completed on the transport path formed by the first conveying mechanism, the third conveying mechanism and the second conveying mechanism. This greatly simplifies the structure of the transmission part, makes the overall structure of the equipment more compact, and greatly shortens the path for the PCB board to be transported between the various processes, thereby significantly improving work efficiency.

[0042] On the other hand, the design of the warehouse-type preheating mechanism greatly reduces the footprint of the equipment, better controls the temperature zone and facilitates future maintenance.

[0043] On the other hand, the rotary welding mechanism is equipped with two rotatable welding furnaces to perform different welding processes on different positions of the same PCB board. It can be targeted to set welding furnaces to adapt to different solder joint sizes, while meeting the requirements of different welding processes. It has a compact structure and high welding efficiency.

[0044] On the other hand, by setting up an adjustment component, a height difference is formed between the rotation and welding positions of the two welding furnaces to prevent the welding furnaces from colliding with the PCB board during rotation and causing damage to the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] 1( a ) and ( b ) are schematic diagrams 1 and 2 of a fully automatic selective soldering system for PCB boards according to an embodiment of the present invention.

[0046] FIG2 is a three-dimensional diagram of the flux spraying mechanism, the first conveying mechanism, and the preheating mechanism in FIG1 .

[0047] FIG3 is a perspective view of the flux spraying mechanism in FIG2 .

[0048] FIG4 is a perspective view of the first conveying mechanism in FIG2 .

[0049] FIG5 is a three-dimensional view of the first conveying mechanism in FIG2 from another angle.

[0050] FIG6 is an enlarged view of the positioning assembly in FIG5 .

[0051] FIG7 is a perspective view of the preheating unit and the third conveying mechanism in FIG2 .

[0052] FIG8 is a perspective view of the rotary welding mechanism, the second conveying mechanism, and the moving mechanism in FIG1 .

[0053] FIG. 9 is a perspective view of the rotary welding mechanism in FIG. 8 .

[0054] FIG10 is a front view of the rotary welding mechanism in FIG9 .

[0055] FIG. 11 is a side view of the spin welding mechanism in FIG. 9 . Modes for Carrying Out the Invention

[0056] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0057] Referring to Figure 1, the present invention provides a fully automatic selective soldering system for PCBs. The system comprises a housing, a flux spraying mechanism 1 disposed within the housing, a first conveying mechanism 2, a preheating mechanism 3, a rotary soldering mechanism 10, a second conveying mechanism 20, a moving mechanism 30, and a control unit. PCB inlets a and outlets b are provided on either side of the housing. The first conveying mechanism 2 interfaces with the PCB inlet a for loading PCBs to be processed. The second conveying mechanism 20 interfaces with the PCB outlet b for unloading soldered PCBs.

[0058] The flux spraying mechanism 1, the first conveying mechanism 2, and the preheating mechanism 3 form a PCB pre-soldering device for spraying flux and preheating the PCB. As shown in Figure 2, the flux spraying mechanism 1 is located below the first conveying mechanism 2 and is used to spray flux onto the areas of the PCB to be soldered.

[0059] Referring also to Figure 3, the flux spraying mechanism 1 specifically comprises an XY-axis module 101, a vision component 102 mounted on the XY-axis module 101, and a spray gun 103. The XY-axis module 101 drives the vision component 102 and spray gun 103 in the X- and Y-axis directions. The vision component 102 and spray gun 103 are positioned adjacent to each other. The flux spraying mechanism 1 is connected to a control unit. The control unit's vision module calculates data based on the PCB image information obtained by the vision component. This data then controls the XY-axis module 101 to move the spray gun 103 to a designated position for precise spraying. The flux is precisely sprayed on the desired soldering area on the bottom surface of the PCB, rather than on the entire PCB. This avoids contamination outside the solder joints and enables simple and precise spraying.

[0060] The first conveyor mechanism 2 is used to load the PCBs to be processed and transport them to the spraying station of the flux spraying mechanism 1. As shown in Figure 4 , the first conveyor mechanism 2 includes a bracket 21, two first conveyor rails 22 arranged side by side, a first roller assembly 23 mounted on the first conveyor rails 22, and a first conveyor motor 24 that drives the first roller assembly 23. The PCBs 100 are moved by the two first roller assemblies 23. In other embodiments, the first roller assembly 23 can be replaced with a chain drive.

[0061] The first conveying mechanism 2 also includes a width adjustment assembly 25 for adjusting the width between the two first conveying rails 22. The width adjustment assembly 25 includes a width adjustment screw rod 251, a width adjustment screw rod nut 252, and a width adjustment motor 253. The width adjustment screw rod 251 and the width adjustment screw rod nut 252 drive one of the first conveying rails 22 to move closer to or away from the other first conveying rail 22. Preferably, the width adjustment assembly 25 includes two sets of parallel width adjustment screw rods 251 and width adjustment screw rod nuts 252. The width adjustment motor 253 drives the two width adjustment screw rods 251 to move simultaneously through gear transmission.

[0062] Please refer to Figures 2 and 5, the first conveying mechanism 2 also includes a height adjustment component 26, which includes a height adjustment screw, a height adjustment screw nut and a height adjustment motor. The height adjustment screw nut is fixedly connected to the bracket to adjust the height of the first conveying track 22 and the first roller group 23.

[0063] As shown in Figures 5 and 6 , the first conveyor mechanism 2 also includes positioning assemblies 27, one each mounted on the two first conveyor rails 22. Each positioning assembly 27 comprises a positioning cylinder 271, an output rod 272, a support base 273, and a positioning plate 274, which are connected in sequence. The positioning cylinder drives the positioning plate 274 to move perpendicularly to the PCB board. The positioning plate 274 engages and clamps the first roller assembly 23 to secure the PCB board. Furthermore, sensors are provided at the front, middle, and rear ends of the first conveyor mechanism 2. These sensors are signal-connected to a control unit to identify the position of the PCB board 100 entering the first conveyor rail 22 and control the operation of the first conveyor motor 24 and positioning assembly 27 based on the position information of the PCB board 100.

[0064] The preheating mechanism 3 is used to preheat the PCB after spraying. As shown in Figures 2 and 7 , the preheating mechanism 3 is located on one side of the first conveyor mechanism 2 and comprises a plurality of stacked preheating units 31, a third conveyor mechanism 32 located within each preheating unit 31, and a Z-axis module 33. Preferably, in this embodiment, there are three preheating units 31. Each preheating unit 31 is equipped with a separate third conveyor mechanism 32.

[0065] The preheating unit 31 specifically comprises a housing 311 with openings at both ends, an upper preheater and a lower preheater located within the housing 311, with a preheating chamber 312 formed between the upper and lower preheaters. This top-and-bottom heating structure further accelerates preheating and improves preheating efficiency. Preferably, the upper preheater comprises a metal housing and a hot air unit within it, while the lower preheater is a far-infrared lamp. Each preheating unit also features a separate thermostat to precisely control the desired preheating temperature for the product.

[0066] The third conveying mechanism 32 includes two second conveying rails 321 arranged side by side, a second roller set 322 provided on the second conveying rails 321 , and a second conveying motor 323 driving the second roller set 322 .

[0067] The Z-axis module 33 is used to adjust the position of the preheating unit in the Z-axis direction to mate the third conveying mechanism 32 with the first conveying mechanism 22. Specifically, each preheating unit 31 is fixed to the Z-axis module 33. The Z-axis module 33 drives the preheating unit 31 up and down, allowing each third conveying mechanism 32 to mate with the first conveying mechanism 22 when needed to transfer the sprayed PCB board to the preheating unit 31. The combination of the Z-axis module 33 and the multi-layer preheating unit 31 significantly reduces the equipment's footprint, improving temperature zone control and equipment maintenance. Furthermore, the multi-layer preheating unit 31 can be used simultaneously, significantly improving the efficiency of pre-soldering treatment of the PCB board 100.

[0068] The rotary welding mechanism 10 is used to weld the points to be welded on the PCB. As shown in Figure 8 , the second conveying mechanism 20 is located above the rotary welding mechanism 10 and is used to transport the preheated PCB from the preheating mechanism 3 to the top of the rotary welding mechanism 10. The moving mechanism 30 is located below the rotary welding mechanism 10 to drive the rotary welding mechanism 10. The moving mechanism 30 includes an X-axis module 301 and a Y-axis module 302.

[0069] 9 and 10 , the rotary soldering mechanism 10 includes a base 11, a soldering assembly 12, a rotating assembly 13, a lifting assembly 14, and an adjusting assembly 15. The soldering assembly 12 includes a main fixed plate 120 and two soldering furnaces 121 movably mounted on the main fixed plate 120. The soldering furnaces 121 spray tin peaks to perform soldering from the bottom of the PCB.

[0070] Two intelligent electromagnetic induction pump solder pots enable multi-process soldering on a single board. The solder pot temperature, nitrogen temperature, wave peak height, and wave peak correction are all computer-configurable. The solder pot liner is made of titanium alloy and is leak-proof. In other embodiments, the solder pots can be interchanged with existing solder pots on existing machines. All connections require quick-connect sockets, eliminating the need for wiring.

[0071] Specifically, the soldering furnace 121 includes a furnace body 122, a nozzle 123, an upper fixing plate 124 for securing the furnace body 122, a lower fixing plate 125, and a plurality of fixing rods 126 connecting the upper fixing plate 124 and the lower fixing plate 125. The upper fixing plate 124 is arranged circumferentially around the furnace body 121. The fixing rods 126 extend through the main fixing plate 120, allowing the soldering furnace 121 to move up and down relative to the main fixing plate 120. The main fixing plate 120 is provided with a linear bearing 127, and the lower surface of the upper fixing plate 124 is provided with a shaft fixing seat 128 for mounting the fixing rods 126. The nozzle 123 can be a fine-hole nozzle, an elongated nozzle, or a special-shaped nozzle. In this embodiment, the furnace body 122 is an intelligent electromagnetic induction pump soldering furnace, comprising a titanium inner liner and an external heating plate.

[0072] 9 and 11 , the rotating assembly 13 is disposed on the base 11 and is used to drive the welding assembly 12 to rotate. The rotating assembly 13 includes a fixed gear 131 fixed to the base 11, a rotating bearing, a rotating shaft, a rotating motor 134 fixed to the rotating shaft, and a movable gear 135 driven by the rotating motor 134. The movable gear 135 engages with the fixed gear 131 to drive the rotating shaft and the welding assembly 12 to rotate. By configuring the rotating assembly 13 to drive the two welding furnaces 121 to rotate and translocate, welding can be performed on different positions of the same PCB board. This allows for the specific configuration of welding furnaces that are adapted to different solder joint sizes, while meeting the requirements of different welding processes. The structure is compact and the welding efficiency is high.

[0073] The lifting assembly 14 is used to drive the welding assembly 12 to move up and down. Referring to Figures 9, 10, and 11, the lifting assembly 14 includes a rotating platform 141 fixed to a rotating shaft, a lifting motor 142, a screw rod 143, and a scissor arm 144 disposed on the rotating platform 141. The scissor arm 144 is disposed between the main fixed plate 120 and the rotating platform 141. The lifting motor 142 drives the main fixed plate 120 to move up and down through the screw rod 143 and scissor arm 144, thereby driving the two welding furnaces 121 to move up and down.

[0074] Adjustment assembly 15 is used to create a height difference between the two welding furnaces 121. As shown in FIG10 , adjustment assembly 15 includes a cam 151 disposed on base 11 and a fisheye bearing 152 disposed at the bottom of welding furnace 121. Cam 151 is located in the rotational direction of welding furnace 121. When one welding furnace 121 rotates above cam 151, fisheye bearing 152 cooperates with cam 151 to lift welding furnace 121. By providing the adjustment assembly, a height difference is formed between the rotational and welding positions of the two welding furnaces, preventing the two welding furnaces 121 from colliding with the PCB during rotation and causing damage to the product.

[0075] As shown in Figure 9, the rotary welding mechanism 10 also includes a vision component 16 and a laser temperature compensation component (not shown). The vision component 16 is used to optically capture and inspect the PCB 100 being welded. The vision component 16 is located on the upper surface of the main fixing plate 120 and between the welding furnaces 121. The mechanism also includes an AOI inspection module (not shown) that directly checks the solder joint yield after soldering is complete. Based on the results, it determines whether the PCB needs to be re-welded or removed from the welding station, generating an alarm.

[0076] The laser heating assembly is located above the main mounting plate 120 and near the nozzle 123 to provide heating for the PCB. This heating function is determined by the product's production process. PCBs further from the preheating zone may experience lower temperatures, affecting the soldering yield, necessitating heating to achieve a higher soldering yield.

[0077] The structure of the second conveyor mechanism 20 is identical to that of the first conveyor mechanism 2 and is not further described here. After the PCB is transported online by the second conveyor mechanism 20 and positioned at the designated location, the vision component 16 first calculates the location of the PCB to be soldered. The control system then calculates the accurate value and drives the movement mechanism 30 to accurately move the rotary welding mechanism 10 to the designated location for precise soldering.

[0078] The first conveying mechanism 2 and the second conveying mechanism 20 are respectively located on both sides of the preheating mechanism 3. During operation, the first conveying mechanism 2, the third conveying mechanism 32 and the second conveying mechanism 20 are connected in sequence to form a linear module, which transports the PCB boards to the spraying station, the preheating station and the welding station in sequence. The first conveying mechanism 2, the third conveying mechanism 32 and the second conveying mechanism 20 not only play a conveying role, but also are used to carry the PCB boards in the above three stations. There is no need to set up separate carrying mechanisms for each section. On the one hand, the structure of the transmission part is greatly simplified, making the overall structure of the equipment more compact; on the other hand, the transmission path of the PCB boards between the various processes is greatly shortened, which greatly improves work efficiency.

[0079] Terms such as "upper," "lower," "front," and "back" used herein to denote relative spatial positions are used for ease of explanation to describe the relationship of one feature relative to another, as shown in the accompanying drawings. It should be understood that, depending on the placement of the product, these terms may be intended to encompass orientations other than those depicted in the drawings and should not be construed as limitations on the claims.

[0080] In addition, the above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. The understanding of this specification should be based on technical personnel in the relevant technical field. Although this specification has described the present invention in detail with reference to the above embodiments, ordinary technical personnel in the field should understand that technical personnel in the relevant technical field can still modify or replace the present invention with equivalents, and all technical solutions and improvements that do not depart from the spirit and scope of the present invention should be covered by the scope of the claims of the present invention.

Claims

1. A fully automatic selective soldering system for PCB boards, characterized in that: Including the settings in sequence A flux spraying mechanism is used to spray flux onto the part of the PCB to be soldered; The first conveying mechanism is used to convey the PCB board to the spraying station of the flux spraying mechanism; A preheating mechanism, used for preheating the PCB board after spraying, wherein the preheating mechanism is a warehouse-type preheating mechanism with at least two layers, and a third conveying mechanism and a Z-axis module are provided in the preheating mechanism; The second conveying mechanism is used to convey the preheated PCB board to the top of the rotary welding mechanism; Rotary welding mechanism, used to weld the preheated PCB board; The flux spraying mechanism is located below the first conveying mechanism, the rotary welding mechanism is located below the second conveying mechanism, and the first conveying mechanism and the second conveying mechanism are respectively connected to two ends of the third conveying mechanism.

2. The fully automatic selective soldering system for PCB boards as claimed in claim 1, characterized in that: The preheating mechanism comprises at least two stacked preheating units, each layer of the preheating units is provided with the third conveying mechanism, and the Z-axis module is used to adjust the position of the preheating unit in the Z-axis direction to dock the first conveying mechanism with the third conveying mechanism; The preheating unit comprises an upper preheater and a lower preheater, and a preheating chamber is formed between the upper preheater and the lower preheater; The upper preheater comprises a metal shell and a hot air unit therein, and the lower preheater is a far-infrared lamp; each of the preheating units also comprises a temperature controller.

3. The fully automatic selective soldering system for PCB boards as claimed in claim 1, characterized in that: The first conveying mechanism includes a bracket, two first conveying tracks arranged side by side, a first roller group or a first chain arranged on the first conveying track, and a first conveying motor driving the first roller group or the first chain, and the PCB board moves under the drive of the two first roller groups or the first chain; The first conveying mechanism further includes a width adjustment component, which includes a width adjustment screw rod, a width adjustment screw rod nut and a width adjustment motor, and the width adjustment screw rod and the width adjustment screw rod nut drive one of the first conveying tracks to approach or move away from the other first conveying track; The first conveying mechanism further includes a height adjustment component, which includes a height adjustment screw, a height adjustment screw nut and a height adjustment motor, and the height adjustment screw nut is fixedly connected to the bracket to adjust the height of the first conveying track and the first roller group or the first chain; The first conveying mechanism also includes positioning components respectively arranged on the two first conveying rails, each positioning component includes a positioning cylinder, an output rod, a support seat and a positioning plate connected in sequence, the positioning cylinder drives the positioning plate to move in a direction perpendicular to the PCB board, and the positioning plate cooperates with the first roller group or the first chain to clamp the PCB board to fix the PCB board.

4. The fully automatic selective soldering system for PCB boards as claimed in claim 1, characterized in that: The rotary welding mechanism comprises a base and a welding assembly, and the welding assembly comprises two welding furnaces movably arranged on a main fixed plate; The rotary welding mechanism also includes a rotating component arranged on the base and driving the welding component to rotate, and a lifting component driving the welding component to rise and fall.

5. The fully automatic selective soldering system for PCB boards as claimed in claim 4, characterized in that: The rotary welding mechanism further comprises an adjusting assembly, wherein the adjusting assembly comprises a cam capable of adjusting the height difference between the two welding furnaces; The adjusting assembly is suitable for preventing the two welding furnaces from colliding with the PCB board during the rotation process; The cam is located on the rotating circumference of the welding furnace, and a fisheye bearing is provided at the bottom of the welding furnace. When one of the welding furnaces rotates to above the cam, the fisheye bearing cooperates with the cam to lift up the welding furnace.

6. The fully automatic selective soldering system for PCB boards as claimed in claim 4, characterized in that: The welding furnace comprises a furnace body, a nozzle, an upper fixing plate and a lower fixing plate for fixing the furnace body, and a plurality of fixing rods connecting the upper fixing plate and the lower fixing plate, wherein the upper fixing plate is arranged on the circumference of the furnace body; The fixing rod is passed through the main fixing plate, the welding furnace can move up and down relative to the main fixing plate, a linear bearing is arranged on the main fixing plate, and a shaft fixing seat for mounting the fixing rod is arranged on the lower surface of the upper fixing plate.

7. The fully automatic selective soldering system for PCB boards as claimed in claim 4, characterized in that: The rotating assembly includes a fixed gear fixed on the base, a rotating bearing, a rotating shaft, a rotating motor fixed to the rotating shaft, and a movable gear driven by the rotating motor. The movable gear meshes with the fixed gear to drive the rotating shaft and the welding assembly to rotate.

8. The fully automatic selective soldering system for PCB boards as claimed in claim 4, characterized in that: The lifting assembly includes a rotating platform fixed to the rotating shaft, a lifting motor, a screw rod and a scissor arm arranged on the rotating platform, the scissor arm is arranged between the main fixed plate and the rotating platform, and the lifting motor drives the main fixed plate to rise and fall through the screw rod and the scissor arm.

9. The fully automatic selective soldering system for PCB boards as claimed in claim 1, characterized in that: The rotary welding mechanism also includes a visual component, which is used for optical collection and detection of the PCB board and is arranged on the upper surface of the main fixed plate and between the welding furnaces; The rotary welding mechanism also includes a laser temperature compensation component, which is arranged above the main fixing plate and close to the nozzle to heat and compensate the temperature of the PCB board; It also includes a moving mechanism disposed below the rotary welding mechanism, and is used to drive the rotary welding mechanism to move in a horizontal direction; It also includes an AOI inspection module, which can directly check the yield of the solder joints after soldering is completed, and determine whether the PCB board needs to be re-soldered or moved out of the workstation based on the results and an alarm prompt.

10. A fully automatic selective soldering method for a PCB board, using the fully automatic selective soldering system for a PCB board as claimed in any one of claims 1 to 9 to operate the PCB board, characterized in that: S1: PCB feeding and transmission: The PCB is transported to the spraying station of the flux spraying mechanism through the first conveying mechanism; S2: Use the vision module and electronic spray gun to spray the PCB accurately; S3: Control the third conveying mechanism to dock with the first conveying mechanism through the Z-axis module, so that the sprayed PCB board can be placed in different layers of the preheating mechanism for preheating respectively; S4: The preheated PCB board can be transported to the top of the rotary welding mechanism by docking the third conveying mechanism with the second conveying mechanism; S5: welding the preheated PCB board through the rotary welding mechanism.

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