A lead-free wave soldering apparatus and soldering method for PCB boards

Abstract

This invention relates to the field of wave soldering technology, specifically to a lead-free wave soldering apparatus and method for PCB boards. The lead-free wave soldering apparatus includes a conveying mechanism, which in turn includes a flipping conveying module. The flipping conveying module includes a connecting bracket, two flip plates (first type), two flip plates (second type), four short plates, four elastic telescopic rods, four connecting arms, two microswitches (first type), two microswitches (second type), and two electric telescopic rods. The connecting bracket, short plates, elastic telescopic rods, and connecting arms are sequentially rotatably connected to form a four-bar linkage. When one side of the PCB board simultaneously contacts two microswitches (first type), the electric telescopic rods retract inward, flip plates (first and second types) flip relative to each other until they are in contact, thereby triggering the two microswitches (second type). The electric telescopic rods then open outward, flip plates (first and second types) flip back to back until they return to their initial positions, thus flipping the PCB board. This invention enables automatic flipping and conveying of PCB boards, improving conveying efficiency and processing safety.

Description

Technical Field

[0001] This invention relates to the field of wave soldering technology, and in particular to a lead-free wave soldering apparatus for PCB boards and a soldering method for the lead-free wave soldering apparatus for PCB boards. Background Technology

[0002] Wave soldering is a commonly used process for PCB manufacturing due to its high efficiency, low cost, and environmental friendliness. Lead-free wave soldering, also known as lead-free wave soldering, is an environmentally friendly soldering method designed to reduce or completely eliminate harmful substances, especially lead, released during the soldering process. Traditional wave soldering uses lead-containing solder, while lead-free wave soldering uses lead-free solder as the soldering material. The principle of lead-free wave soldering is similar to traditional wave soldering: immersing the components to be soldered in molten solder and completing the soldering process through pouring and slag removal.

[0003] Some existing PCBs require double-sided lead-free wave soldering. During this process, the PCB needs to be wave soldered on one side first, then the liquid solder is cooled and solidified before the PCB is flipped for further processing. PCB flipping and transport can be done manually or mechanically. However, because PCBs are preheated, they are difficult to cool down quickly, posing a risk of burns for manual flipping. Mechanical flipping often requires high-precision robotic arms, resulting in high equipment and R&D costs. Furthermore, if the PCB cools to room temperature, double-sided processing requires repeated preheating, reducing processing efficiency and increasing production costs. Summary of the Invention

[0004] Therefore, it is necessary to address the problem that existing lead-free wave soldering equipment has difficulty in quickly flipping PCB boards to achieve double-sided wave soldering, resulting in high production costs and low efficiency. To address this, a lead-free wave soldering equipment and soldering method for PCB boards is proposed.

[0005] The present invention is achieved through the following technical solution: a lead-free wave soldering device for PCB boards, comprising a body and a conveying mechanism.

[0006] The conveying mechanism includes a front-end conveying module, a flipping conveying module, and a sorting conveying module. The front-end conveying module is installed inside the main body and is used to convey PCB boards along the production line direction. The sorting conveying module is installed on the outside of the main body and is used to convey the soldered PCB boards to the next process. The flipping conveying module includes a connecting bracket, two flip plates (first type), two flip plates (second type), four short plates, four elastic telescopic rods, four connecting arms, two microswitches (first type), two microswitches (second type), and two electric telescopic rods. The connecting bracket is installed between the front-end conveying module and the sorting conveying module. Each short plate, elastic telescopic rod, and connecting arm is sequentially rotatably connected to form a four-bar linkage. The four four-bar linkages are rotatably connected to both sides of the connecting bracket. Two flip plates (first type) are installed on the two short plates closest to the front-end conveying module. Two flip plates (second type) are installed on the two short plates closest to the sorting conveying module. Two microswitches (first type) are installed on the two flip plates (first type). Two microswitches (second type) are installed on the two flip plates (second type). Two electric telescopic rods are located on both sides of the connecting bracket, and their ends are rotatably connected to the connection points of the connecting arms and the elastic connecting rods. Microswitch 1 and microswitch 2 are electrically connected to the electric telescopic mast. When both microswitches 1 are closed, the electric telescopic mast retracts inward. When both microswitches 2 are closed, the electric telescopic mast opens outward.

[0007] The aforementioned lead-free wave soldering device transports the PCB board from its main body to the outside via a front-end conveying module. The PCB board slides down along a flip plate until one side of the PCB board simultaneously contacts two microswitches. At this point, the electric telescopic rod retracts inward, and flip plates one and two flip plates flip against each other until they are in contact. Simultaneously, two microswitches two are triggered, causing the electric telescopic rod to open outward. Flip plates one and two flip plates flip back to their initial positions, and the PCB board moves with flip plate two to the sorting and conveying module, completing the flipping process. This invention can flip and transport PCB boards after wave soldering, maintaining wave soldering quality while improving transport efficiency and avoiding the risks associated with manual flipping. Furthermore, it allows for double-sided wave soldering of the flipped PCB board, improving processing efficiency and reducing processing costs.

[0008] Furthermore, a limiting component is installed on the flap plate, which includes a limiting strip, a screw, and a nut. The limiting strip is slidably connected to the flap plate. One end of the screw is rotatably connected to the limiting strip, and the other end is screwed to the nut. The nut is fixedly connected to the flap plate.

[0009] Furthermore, an adjustment assembly is installed on the second flap, which includes a second limiting strip, a second screw, a second nut, an adjusting block, and an airbag. The second limiting strip is slidably connected to the second flap. One end of the second screw is rotatably connected to the second limiting strip, and the other end is screwed to the second nut. The second nut is fixedly connected to the second flap. The adjusting block is slidably connected to the second limiting strip. One end of the airbag is fixedly connected to the adjusting block, and the other end is fixedly connected to the second limiting strip.

[0010] Furthermore, the sorting and conveying module includes an identification submodule, an output submodule, and a return submodule. The identification submodule is used to determine whether the PCB board has completed wave soldering. The output submodule is used to output the PCB board that has completed wave soldering. The return submodule is used to re-convey the PVB board that has not completed wave soldering back into the main body.

[0011] Furthermore, it also includes a flux spraying mechanism, a preheating mechanism, a wave soldering generator, and a cooling mechanism. The flux spraying mechanism is used to spray flux onto the PCB board. The preheating mechanism is used to heat the PCB board to a preset temperature. The wave soldering generator is used to output liquid solder with a wave peak. The cooling mechanism is used to cool the PCB board after wave soldering.

[0012] The present invention also provides a soldering method for a lead-free wave soldering apparatus for PCB boards, comprising the following steps:

[0013] S1: The front-end conveying module conveys the PCB board to be soldered into the main body, and then passes through the flux spraying mechanism, the preheating mechanism, and the wave soldering generating mechanism in sequence, so that the PCB board is sprayed with flux, heated to the preset temperature, and wave soldered in sequence.

[0014] S2: The PCB board is output from the main body and slides down along the flip plate until one side of the PCB board contacts two micro switches at the same time. This activates the electric telescopic rod to retract inward. The flip plate and the flip plate flip inward until the two micro switches trigger, which in turn activates the electric telescopic rod to open outward, so that the PCB board moves with the flip plate to the sorting and conveying module.

[0015] S3: The identification submodule determines whether the PCB has completed wave soldering. If not, the return submodule is used to transport the PCB back into the main body. If it has been completed, the PCB is transported to the next process.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] This invention uses a front-end conveying module to transport PCB boards from inside the main body to the outside. The PCB board slides down along a flip plate until one side of the PCB board simultaneously contacts two microswitches. At this point, the electric telescopic rod retracts inward, and flip plates one and two flip plates flip against each other until they are in contact. Simultaneously, two microswitches two are triggered, causing the electric telescopic rod to open outward. Flip plates one and two flip against each other until they return to their initial positions. The PCB board then moves with flip plate two to the sorting and conveying module, completing the flipping process. This invention can flip and transport PCB boards after wave soldering, maintaining wave soldering quality while improving transport efficiency and avoiding the risks associated with manual flipping. Furthermore, it allows for double-sided wave soldering of the flipped PCB board, improving processing efficiency and reducing processing costs.

[0018] This invention adjusts the position of the first limiting strip by rotating screw one, ensuring the distance between the two limiting strips is slightly greater than the width of the PCB board. This keeps the PCB board precisely positioned on the two flip plates, preventing it from falling and avoiding collisions between the solder bars formed during wave soldering and the flip plates, thus maintaining good soldering quality. Rotating screw two adjusts the distance between the two second limiting strips, aligning their positions with the first limiting strip. Furthermore, the flip plates one and two compress the airbag, causing the adjusting block to move inwards towards the two second flip plates, adjusting the position of the PCB board within them so that it is precisely centered on the two flip plates, ensuring a smooth connection to the sorting and conveying module. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the lead-free wave soldering device for PCB boards in Embodiment 1 of the present invention;

[0020] Figure 2 for Figure 1 A partial three-dimensional structural diagram of the inverted conveyor module;

[0021] Figure 3 for Figure 1 A three-dimensional breakdown diagram of the operation of the inverted conveyor module;

[0022] Figure 4 for Figure 3 A front view action breakdown diagram of the flipping conveyor module;

[0023] Figure 5 This is a step diagram of the soldering method of the lead-free wave soldering apparatus for PCB boards according to Embodiment 2 of the present invention.

[0024] In the diagram: 1. Main body; 2. Conveying mechanism; 21. Front-end conveying module; 22. Tilting conveying module; 221. Connecting bracket; 222. Flip plate one; 223. Flip plate two; 224. Short plate; 225. Elastic telescopic rod; 226. Connecting support arm; 227. Micro switch one; 228. Micro switch two; 229. Electric telescopic rod; 23. Sorting conveying module; 231. Identification submodule; 232. Output submodule; 233. Return submodule; 24. Limiting component; 241. Limiting bar one; 242. Screw one; 243. Nut one; 25. Adjusting component; 251. Limiting bar two; 252. Screw two; 253. Nut two; 254. Adjusting block; 255. Airbag; 3. Flux spraying mechanism; 4. Preheating mechanism; 5. Wave soldering generating mechanism; 6. Cooling mechanism. Detailed Implementation

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0026] It should be noted that when a component is said to be "installed on" another component, it can be directly on the other component or it may be in a component that is centered on it. When a component is said to be "set on" another component, it can be directly set on the other component or it may also be in a component that is centered on it. When a component is said to be "fixed to" another component, it can be directly fixed to the other component or it may also be in a component that is centered on it.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0028] Example 1

[0029] Please see Figure 1-Figure 2 This embodiment provides a lead-free wave soldering device for PCB boards, including a body 1, a conveying mechanism 2, a flux spraying mechanism 3, a preheating mechanism 4, a wave soldering generating mechanism 5, and a cooling mechanism 6.

[0030] The conveying mechanism 2 includes a front-end conveying module 21, a flipping conveying module 22, and a sorting conveying module 23. The front-end conveying module 21 is installed inside the main body 1 and is used to convey PCB boards along the production line direction. Specifically, the front-end conveying module 21 includes a first horizontal conveying submodule, a lifting conveying submodule, an inclined conveying submodule, and a second horizontal conveying submodule. The first horizontal conveying submodule conveys the PCB boards to be processed from the inlet of the main body 1 to above the flux spraying mechanism 3, where flux is sprayed onto the PCB boards. Subsequently, the lifting conveying submodule conveys the PCB boards to the preheating mechanism 4, allowing multiple PCB boards to be processed to be heated simultaneously, which not only improves heating efficiency and production efficiency but also reduces energy waste. The inclined conveying submodule conveys the PCB boards to the wave soldering generating mechanism 5, allowing the bottom side of the PCB boards to pass through the solder wave peaks for wave soldering. The second horizontal conveying submodule conveys the wave-soldered PCB boards to the cooling mechanism 6 for cooling, allowing the liquid solder to solidify quickly.

[0031] The sorting and conveying module 23 is installed on the outside of the main body 1 and is used to convey the soldered PCB board to the next process. The sorting and conveying module 23 includes an identification submodule 231, an output submodule 232, and a return submodule 233. The identification submodule 231 is used to determine whether the PCB board has completed wave soldering. Some PCB boards require double-sided soldering, so after single-sided wave soldering of the PCB board is completed, it is necessary to determine whether the other side of the PCB board needs to be wave soldered. For example, if the PCB board only needs single-sided wave soldering, it means that wave soldering has been completed. If the PCB board requires double-sided wave soldering and one side has not been wave soldered, it means that wave soldering has not been completed.

[0032] The output submodule 232 is used to output the PCB board that has completed wave soldering. The return submodule 233 is used to re-feed the PCB board that has not completed wave soldering back into the main body 1. In this embodiment, the PCB board that has not completed wave soldering still has priority and is given priority over other unprocessed PCB boards when being fed back into the main body 1. This can retain some of the preheating temperature, reduce resource consumption, lower processing costs, and improve processing efficiency.

[0033] Please combine Figures 3-4 The flipping conveyor module 22 includes a connecting bracket 221, two flip plates 222, two flip plates 223, four short plates 224, four elastic telescopic rods 225, four connecting arms 226, two microswitches 227, two microswitches 228, and two electric telescopic rods 229. The connecting bracket 221 is installed between the front-end conveyor module 21 and the sorting conveyor module 23. Each short plate 224, elastic telescopic rod 225, and connecting arm 226 is rotatably connected in sequence to form a four-bar linkage. The four four-bar linkages are rotatably connected to both sides of the connecting bracket 221. The connecting bracket 221 can be regarded as the frame of the four-bar linkage, and the elastic telescopic rods 225 can be regarded as the connecting rods of the four-bar linkage.

[0034] Two flaps 222 are mounted on two short plates 224 near the front conveyor module 21. Two flaps 223 are mounted on two short plates 224 near the sorting conveyor module 23. Flips 222 and 223 are positioned opposite each other. Initially, flaps 222 are tilted downwards, while flaps 223 are horizontal. Two microswitches 227 are mounted on the two flaps 222 respectively. Two microswitches 228 are mounted on the two flaps 223 respectively.

[0035] Two electrically operated telescopic rods 229 are positioned on either side of the connecting bracket 221, with both ends of each rod rotatably connected to the connection points of the connecting arm 226 and the elastic connecting rod. Microswitches 227 and 228 are electrically connected to the telescopic rods 229. When both microswitches 227 are closed, the telescopic rods 229 retract inwards. When both microswitches 228 are closed, the telescopic rods 229 open outwards. When the PCB board is conveyed from inside the main body 1 to the outside, it slides down along the first flip plate 222 until one side of the PCB board simultaneously contacts two microswitches 227. At this point, the electric telescopic rod 229 retracts inward, and the first flip plate 222 and the second flip plate 223 flip relative to each other until they are in contact. Simultaneously, two microswitches 228 are triggered, causing the electric telescopic rod 229 to open outward. The first flip plate 222 and the second flip plate 223 flip opposite each other until they return to their initial positions. The PCB board moves with the second flip plate 223 to the sorting and conveying module 23, completing the flipping process. When the first flip plate 222 and the second flip plate 223 are in contact, the electric telescopic rod 229 continues to retract under inertia. This is buffered by the elastic telescopic rod 225 to prevent wear on the first flip plate 222 and the second flip plate 223.

[0036] A limiting component 24 is installed on the flip plate 222. The limiting component 24 includes a limiting strip 241, a screw 242, and a nut 243. The limiting strip 241 is slidably connected to the flip plate 222. One end of the screw 242 is rotatably connected to the limiting strip 241, and the other end is screwed to the nut 243. The nut 243 is fixedly connected to the flip plate 222. According to the width of the PCB board, the screw 242 can be rotated to adjust the position of the limiting strip 241 so that the distance between the two limiting strips is slightly larger than the width of the PCB board. This keeps the PCB board just on the two flip plates 222, preventing the PCB board from falling off, and also preventing the solder bars formed by wave soldering from colliding with the flip plates 222, thus maintaining good soldering quality.

[0037] An adjustment assembly 25 is installed on the second flap 223. The adjustment assembly 25 includes a second limiting strip 251, a second screw 252, a second nut 253, an adjustment block 254, and an airbag 255. The second limiting strip 251 is slidably connected to the second flap 223. One end of the second screw 252 is rotatably connected to the second limiting strip 251, and the other end is screwed to the second nut 253. The second nut 253 is fixedly connected to the second flap 223. The adjustment block 254 is slidably connected to the second limiting strip 251. One end of the airbag 255 is fixedly connected to the adjustment block 254, and the other end is fixedly connected to the second limiting strip 251. By rotating the second screw 252, the distance between the two second limiting strips 251 can be adjusted so that the positions of the two second limiting strips 251 match those of the first limiting strip 241. In addition, the airbag 255 is squeezed by the first flip plate 222 and the second flip plate 223, causing the adjusting block 254 to move inward to the inside of the two second flip plates 223, thereby adjusting the position of the PCB board inside the two second flip plates 223 so that the PCB board is exactly in the center of the two second flip plates 223 and is well connected to the sorting and conveying module 23.

[0038] The lead-free wave soldering device in this embodiment can flip and transport the PCB board after wave soldering. At the same time, it can adjust the spacing between flip plate 1 222 and flip plate 223 according to the size of the PCB board, and adjust the position of the PCB board so that the PCB board transitions from the front-end conveying module 21 to the sorting and conveying module 23. While maintaining the wave soldering quality, it realizes the flipping and transporting of the PCB board, improves the conveying efficiency, avoids the risks of manual flipping, and can perform double-sided wave soldering on the flipped PCB board, improving processing efficiency and reducing processing costs.

[0039] Example 2

[0040] Please see Figure 5 This embodiment provides a soldering method for a lead-free wave soldering device for PCB boards, including the following steps:

[0041] S1: The front-end conveying module 21 conveys the PCB board to be soldered into the main body 1, and then passes through the flux spraying mechanism 3, the preheating mechanism 4, and the wave soldering generating mechanism 5 in sequence, so that the PCB board is sprayed with flux, heated to the preset temperature, and wave soldered in sequence.

[0042] S2: The PCB board is output outside the main body 1. The PCB board slides down along the flip plate 222 until one side of the PCB board contacts two micro switches 227 at the same time. Then the electric telescopic rod 229 is activated to retract inward. The flip plate 222 and the flip plate 223 flip inward relative to each other until the two micro switches 228 are triggered. Then the electric telescopic rod 229 is activated to open outward, so that the PCB board moves with the flip plate 223 onto the sorting and conveying module 23.

[0043] S3: The identification submodule 231 determines whether the PCB has completed wave soldering. If it has not been completed, the return submodule 233 is used to transport the PCB back into the main body 1. If it has been completed, the PCB is transported to the next process.

[0044] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A lead-free wave soldering apparatus for PCB boards, characterized in that, include: ontology; The conveying mechanism includes a front-end conveying module, a flipping conveying module, and a sorting conveying module. The front-end conveying module is installed inside the main body and is used to convey PCB boards along the production line direction. The sorting conveying module is installed on the outside of the main body and is used to convey the soldered PCB boards to the next process. The flipping conveying module includes a connecting bracket, two flip plates, two flip plates, four short plates, four elastic telescopic rods, four connecting arms, two micro switches, two micro switches, and two electric telescopic rods. The connecting bracket is installed between the front-end conveying module and the sorting conveying module. Each short plate, elastic telescopic rod, and connecting arm is rotatably connected in sequence to form a four-bar linkage. The four four-bar linkages are rotatably connected to the front-end conveying module and the sorting conveying module. The connecting bracket has two sides; two flaps are mounted on two short plates near the front conveying module; two flaps are mounted on two short plates near the sorting conveying module; two microswitches are mounted on the two flaps; two microswitches are mounted on the two flaps; two electric telescopic rods are arranged on both sides of the connecting bracket, and the two ends of the electric telescopic rods are rotatably connected to the connection between the connecting arm and the elastic telescopic rod; the microswitches are electrically connected to the electric telescopic rods; when the two microswitches are closed, the electric telescopic rods retract inward; when the two microswitches are closed, the electric telescopic rods open outward. A limiting component is installed on the flip plate, which includes a limiting strip, a screw, and a nut. The limiting strip is slidably connected to the flip plate. One end of the screw is rotatably connected to the limiting strip, and the other end is screwed to the nut. The nut is fixedly connected to the flip plate. An adjustment assembly is installed on the second flap, which includes a second limiting strip, a second screw, a second nut, an adjusting block, and an airbag. The second limiting strip is slidably connected to the second flap. One end of the second screw is rotatably connected to the second limiting strip, and the other end is screwed to the second nut. The second nut is fixedly connected to the second flap. The adjusting block is slidably connected to the second limiting strip. One end of the airbag is fixedly connected to the adjusting block, and the other end is fixedly connected to the second limiting strip.

2. The lead-free wave soldering apparatus for PCB boards according to claim 1, characterized in that, The sorting and conveying module includes an identification submodule, an output submodule, and a return submodule; the identification submodule is used to determine whether the PCB board has completed wave soldering; the output submodule is used to output the PCB board that has completed wave soldering; and the return submodule is used to re-convey the PCB board that has not completed wave soldering back into the main body.

3. The lead-free wave soldering apparatus for PCB boards according to claim 1, characterized in that, The lead-free wave soldering apparatus also includes: Flux spraying mechanism, used to spray flux onto PCB boards; The preheating mechanism is used to heat the PCB board to a preset temperature. Wave soldering generator, used to output liquid tin with wave peaks; Cooling mechanism, used to cool the PCB board after wave soldering.

4. A soldering method using a lead-free wave soldering apparatus for PCB boards, comprising employing a lead-free wave soldering apparatus for PCB boards as described in any one of claims 1 to 3, characterized in that... The welding method includes the following steps: S1: The front-end conveying module conveys the PCB board to be soldered into the main body, and then passes through the flux spraying mechanism, the preheating mechanism, and the wave soldering generating mechanism in sequence, so that the PCB board is sprayed with flux, heated to the preset temperature, and wave soldered in sequence. S2: The PCB board is output from the main body. The PCB board slides down along the flip plate one until one side of the PCB board contacts two micro switches one at the same time. Then the electric telescopic rod is activated to retract inward. The flip plate one and the flip plate two flip inward until the two micro switches two are triggered. Then the electric telescopic rod is activated to open outward, so that the PCB board moves with the flip plate two to the sorting and conveying module. S3: The identification submodule determines whether the PCB has completed wave soldering. If not, the return submodule is used to transport the PCB back into the main body. If it has been completed, the PCB is transported to the next process.

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