Multi-stage drying and temperature and humidity self-adapting device for cleaning circuit board

Abstract

The application discloses a multi-stage drying and temperature and humidity self-adapting device for circuit board cleaning, which comprises a closed drying cavity arranged horizontally, a feeding port and a discharging port are respectively arranged at the front end and the rear end of the drying cavity, a conveying mechanism is internally arranged in the drying cavity, and the two ends of the conveying mechanism respectively extend to the feeding port and the discharging port outside the drying cavity; the inside of the drying cavity is sequentially divided into a first water cutting zone, a second drying zone and a third solidifying zone along the conveying direction of the conveying mechanism, thereby forming multi-stage drying zones, and adjacent drying zones are separated by air curtain isolation devices arranged in the inside of the drying cavity; the device further comprises a sensor array arranged on the side wall of each drying zone of the drying cavity, a water content detection module arranged in the second drying zone and an electric control cabinet arranged at the bottom of the drying cavity. The application has the advantages that the drying effect is good, and energy saving and high efficiency are achieved.

Description

Technical Field

[0001] This invention relates to the field of auxiliary equipment technology for circuit board manufacturing, specifically to a multi-stage drying and temperature and humidity adaptive device for cleaning circuit boards. Background Technology

[0002] Cleaning is an indispensable step in circuit board manufacturing. It removes solder paste residue, oil, dust, and other impurities from the circuit board surface, ensuring the soldering quality and electrical performance of the circuit board. After cleaning, a large amount of moisture remains on the circuit board surface. If it is not thoroughly dried, the moisture can lead to problems such as oxidation, short circuits, and solder joint detachment, seriously affecting the product qualification rate.

[0003] Currently, existing circuit board cleaning and drying devices suffer from the following drawbacks: First, the drying method is limited, often employing a single-stage or simple two-stage drying structure without clear functional zones. This prevents the implementation of a progressive drying process—removing surface water, removing residual water, and curing—leading to incomplete drying and surface oxidation. Second, fixed temperature and humidity parameters prevent dynamic adjustment based on the real-time moisture content of the circuit board and changes in ambient temperature and humidity. This results in poor adaptability, making it difficult to meet the drying needs of circuit boards of different specifications and moisture contents, and also leads to high energy consumption. Third, the fixed structure of core components (such as air knives, air ducts, and conveying mechanisms) hinders flexible adjustment, resulting in poor water removal, uneven hot air distribution, and scratches on the circuit board surface. Fourth, the lack of an effective heat recovery mechanism leads to the direct emission of waste heat generated during the drying process, resulting in significant energy waste. Fifth, the absence of effective isolation between drying zones causes mutual interference between temperature and humidity levels, leading to unstable drying parameters and further affecting drying quality. Summary of the Invention

[0004] This invention addresses the problems of poor drying effect and high energy consumption mentioned in the background art by providing a multi-stage drying and temperature / humidity adaptive device for circuit board cleaning, including a horizontally arranged sealed drying chamber. The drying chamber has an inlet and an outlet at its front and rear ends, respectively. A conveying mechanism is installed inside the drying chamber, with its two ends extending to the inlet and outlet outside the drying chamber, respectively. The interior of the drying chamber is divided into a primary water-cutting zone, a secondary drying zone, and a tertiary curing zone along the conveying direction of the conveying mechanism, forming a multi-level drying zone. Adjacent drying zones are separated by an air curtain isolation device installed inside the drying chamber. It also includes a sensor array installed on the side walls of each drying zone of the drying chamber, a moisture content detection module installed in the secondary drying zone, and an electrical control cabinet installed at the bottom of the drying chamber. The electrical control cabinet integrates a main controller. The sensor array and the moisture content detection module are connected to the main controller via signals. The main controller is connected to the actuators of each multi-stage drying unit for control, together forming a temperature and humidity adaptive control system.

[0005] After the circuit board is cleaned, it enters the conveying mechanism through the feed inlet at the front of the drying chamber. The conveying mechanism drives the circuit board to pass through the first-stage water-cutting zone, the second-stage drying zone, and the third-stage curing zone in sequence along the conveying direction, realizing progressive multi-stage drying. The multi-stage drying structure divides the drying process into three progressive stages: water-cutting, drying, and curing. It specifically removes free water on the surface of the circuit board and residual water inside, while simultaneously achieving curing and shaping. This solves the problems of incomplete drying, surface oxidation, and incomplete curing in existing technologies, thus improving the drying quality. An air curtain barrier is formed between adjacent drying zones by an air curtain isolation device, which isolates the airflow and temperature and humidity environment of each zone, avoids mutual interference, ensures that the temperature and humidity parameters of each zone are independently controllable, effectively avoids mutual interference between the temperature and humidity of each zone, ensures the stability of the temperature and humidity parameters of each zone, and further improves the consistency of drying. A sensor array collects temperature and humidity data in each drying zone in real time, while a moisture content detection module detects the moisture content of the circuit boards in real time. Both types of data are transmitted to the main controller in the electrical control cabinet. The online moisture content detection module is installed across the width of the conveyor belt at the end of the secondary drying zone, after the return air vent and before the air curtain isolation device. The main controller analyzes and processes the collected data and sends control commands to each actuator (such as fan, heater, regulating valve, etc.) of the multi-stage drying unit according to the preset drying parameter thresholds and the real-time moisture content of the circuit boards. This adjusts the working parameters (such as speed, power, opening degree, etc.) of each actuator, forming a closed-loop temperature and humidity adaptive control to ensure that the circuit board drying effect meets the standards without manual intervention. It is suitable for circuit boards of different specifications and moisture contents, reducing labor costs and improving production efficiency. After drying, the circuit boards are discharged through the outlet. The overall structure adopts a horizontally arranged closed drying chamber to reduce heat loss and energy consumption, while preventing external dust and impurities from entering and protecting the surface of the circuit boards from contamination; thus achieving the purpose of good drying effect and energy efficiency.

[0006] Preferably, the primary water-cutting zone includes an external high-pressure centrifugal fan, an air filter pressure reducing valve installed in the drying chamber, and multiple sets of air knife assemblies installed in an alternating manner. The multiple sets of air knives are arranged along the conveying direction and connected to the air filter pressure reducing valve. Each air knife assembly includes an air knife body, which has a high-pressure air flow channel and an air outlet slit. A micro electric adjustment mechanism is installed on the side of the air knife body. The actuator of the micro electric adjustment mechanism is connected to a cutting edge of the air outlet slit to drive the cutting edge to move and adjust the slit width. A micro displacement sensor is also installed on the air knife body. The detection end of the micro displacement sensor is aligned with the movable cutting edge of the air outlet slit to monitor the slit width in real time.

[0007] The primary water-cutting zone employs a high-pressure centrifugal fan, an air filter pressure reducing valve, and multiple sets of staggered opposing air knife assemblies to generate high-pressure clean airflow. This airflow is ejected through the outlet slits of the air knife assemblies, quickly removing free water from the circuit board surface. This results in high water-cutting efficiency. Furthermore, the air filter pressure reducing valve filters and reduces the pressure of the high-pressure air, preventing impurities from entering the airflow and avoiding secondary contamination of the circuit board surface. Multiple air knives are positioned along the conveying direction and connected to the air filter valve, ensuring that free water on all parts of the circuit board surface is quickly blown away, improving water-cutting uniformity. The air knife body is equipped with a micro-electric adjustment mechanism and a micro-displacement sensor. The micro-electric adjustment mechanism drives the movable blade of the outlet slit to move, achieving precise adjustment of the outlet slit width. The micro-displacement sensor monitors the slit width in real time and feeds the monitoring signal back to the main controller, forming a closed-loop adjustment to ensure that the outlet slit width remains stable at the preset value, adapting to the water-cutting needs of circuit boards with different thicknesses and surface structures.

[0008] Preferably, the air knife body is equipped with a replaceable slit adjustment module. This module has a reference cutting edge, which engages with the corresponding cutting edge of the air knife body to form an outlet slit. The replaceable slit adjustment module simplifies the adjustment process of the outlet slit reference width, eliminating the need to disassemble the air knife body, reducing maintenance workload and costs, and improving the ease of maintenance. By replacing modules with different reference cutting edges, a wide range of outlet slit width adjustments can be achieved, further expanding the device's adaptability and meeting the water-cutting needs of more circuit board specifications. The slit adjustment module, in conjunction with a micro-electric adjustment mechanism, achieves dual adjustment of "reference width replacement + precise fine-tuning," ensuring stable water-cutting performance while extending the service life of the air knife assembly (eliminating the need for frequent adjustment of the air knife body cutting edge, reducing wear). Preferably, the secondary drying zone includes: The condensation dehumidification module has its air inlet connected to the return air outlet of the secondary drying zone; The centrifugal circulating fan has its air inlet connected to the air outlet of the condensation dehumidification module; A medium-temperature heater is installed at the air outlet of the centrifugal circulating fan; The spiral gradually expanding vortex air duct has its inlet connected to the air outlet of the medium-temperature heater, and its outlet is a slotted opening facing the conveying mechanism. The shell of the vortex duct is also equipped with a fresh air regulating valve, an exhaust pipe, and an exhaust regulating valve.

[0009] Employing a closed-loop airflow circulation structure, combined with a condensation dehumidification module and a medium-temperature heater, continuous drying and heating of the airflow can be achieved, improving drying efficiency while reducing heat loss and lowering energy consumption. The spiral-expanding vortex air duct can transform the drying hot air into a uniform, high-speed, slotted airflow, ensuring that the hot air evenly covers the circuit board surface and avoiding incomplete drying or overheating damage to the circuit board. The fresh air regulating valve and exhaust regulating valve can flexibly adjust the airflow exchange volume, maintaining stable temperature and humidity parameters in the secondary drying zone, adapting to the drying needs of circuit boards with different moisture contents, and further improving drying quality. The closed-loop circulation structure can reduce the entry of external impurities, preventing contamination of the circuit board surface and extending the service life of each component.

[0010] Preferably, the vortex duct is equipped with multiple angle-adjustable guide vanes, each guide vane having a short shaft fixedly connected to both ends. A bearing housing is installed on the outside of the vortex duct, and the short shaft is rotatably connected to the bearing housing. One end of the short shaft of the guide vane extends to the outside of the vortex duct, and a driven synchronous pulley is fixed at the extended end. A common adjusting shaft and a motor are installed on the outside of the vortex duct. An active synchronous pulley corresponding to the position of each driven synchronous pulley is fixed on the common adjusting shaft, and each active synchronous pulley is connected to the driven synchronous pulley through a synchronous transmission component. Adjustable guide vanes allow for flexible adjustment of the hot air flow direction and distribution, ensuring uniform coverage of circuit board surfaces of different sizes and solving the problems of uneven hot air distribution and incomplete local drying in existing technologies. A linkage structure using a common adjusting shaft, synchronous wheel, and synchronous transmission components enables synchronized angle adjustment of all guide vanes, ensuring a uniform and stable airflow field while simplifying the adjustment mechanism and reducing control difficulty and maintenance costs. The short shaft's rotational engagement with the bearing housing ensures smooth and stable rotation of the guide vanes, reducing wear and extending component lifespan. The guide vane angle can be dynamically adjusted according to the real-time drying status of the circuit board, further improving the device's adaptability and drying quality.

[0011] Preferably, a composite sealing adjustment sleeve is connected to the portion of the short shaft that passes through the bearing housing, and the main body of the guide vane is a hollow airfoil structure, the cavity of which forms an airflow channel. The composite sealing adjustment sleeve can effectively seal the gap between the short shaft and the bearing housing, reduce hot air leakage, reduce energy consumption, and prevent impurities from entering, thus extending the service life of the component; the hollow airfoil structure of the guide vane makes the hot air distribution more uniform, improves the drying effect, and can heat itself through internal airflow, avoiding condensation and ensuring stable operation of the guide vane; the hollow structure reduces the weight of the guide vane, reduces the load on the motor and transmission mechanism, reduces energy consumption, and improves the rotational flexibility of the guide vane.

[0012] Preferably, the three-stage curing zone includes a laminar flow fan unit, a rotary dehumidifier, and an electrostatic eliminator. The air inlet of the laminar flow fan unit is connected to the processing air outlet of the rotary dehumidifier, and the outlet is connected downwards to a static pressure chamber. A perforated flow equalization plate is installed at the bottom of the static pressure chamber, and the electrostatic eliminator is installed inside the discharge port at the end of the three-stage curing zone. Using a rotary dehumidifier for deep dehumidification, combined with laminar flow hot air curing, can thoroughly remove residual trace moisture from the circuit board, achieving curing and shaping, preventing the circuit board from becoming damp after drying, and improving the stability and service life of the circuit board. The static pressure chamber and the perforated flow equalization plate work together to form uniform laminar hot air, preventing high-speed airflow from damaging the dried circuit board, while ensuring uniform curing and improving product consistency. The addition of an electrostatic eliminator can effectively neutralize static electricity on the surface of the circuit board, preventing static electricity from attracting dust and impurities, preventing static electricity from damaging electronic components, and further improving the product quality of the circuit board. The parameters of the laminar flow fan unit and the rotary dehumidifier can be dynamically adjusted to adapt to the curing requirements of different specifications of circuit boards, improving the adaptability of the device.

[0013] Preferably, the regeneration duct of the rotary dehumidifier is connected to a regeneration heater, and the heat source of the regeneration duct is drawn from the exhaust waste heat recovery circuit of the secondary drying zone. Utilizing the exhaust waste heat of the secondary drying zone to provide a heat source for the regeneration duct of the rotary dehumidifier achieves waste heat recovery and utilization, significantly reducing the energy consumption of the regeneration heater and achieving energy-saving effects; it eliminates the need for an additional high-temperature heat source, simplifies the device structure, and reduces equipment manufacturing and operating costs.

[0014] Preferably, the conveying mechanism includes: The frame is fixedly installed on the base of the drying chamber; A drive unit and a conveyor belt driven by the drive unit, the conveyor belt being tensioned on the frame; The width adjustment mechanism, integrated on the frame, includes two symmetrically arranged ball screw pairs driven by servo motors, each ball screw pair having a movable bracket connected to it for clamping the conveyor belt sideband. The thickness-adaptive support mechanism includes a ceramic air flotation plate with micropores and elastic edge clamping wheels installed on the side of a movable support. The ceramic air flotation plate is connected to an air passage with independently adjustable air pressure below it, and the ceramic air flotation plate is installed directly below the conveyor belt.

[0015] The width adjustment mechanism allows for flexible adjustment of the conveyor belt clamping width, while the thickness adaptive support mechanism can adapt to circuit boards of different thicknesses through air pressure adjustment. This dual adaptation structure significantly improves the device's adaptability, meeting the conveying needs of circuit boards of different specifications. The ceramic air-floating plate enables contactless conveying of circuit boards, and the limiting function of the elastic edge clamping wheels prevents scratches on the circuit board surface and avoids deviation during conveying, improving conveying stability and circuit board surface quality. The servo motor-driven ball screw pair offers high adjustment precision and stability, ensuring accurate width adjustment and improving conveying consistency. The elastic edge clamping wheels have an elastic buffering effect, preventing excessive clamping force from damaging the circuit board edges, while also adapting to minor dimensional deviations in the circuit boards, enhancing the device's practicality. Specifically, the elastic edge clamping wheels consist of springs, rubber rings, or air pressure buffering elements installed between the wheel body and the mounting bracket. When the clamping wheels are squeezed perpendicular to the conveyor belt direction, they can generate a controllable amount of retraction and automatically reset after release.

[0016] Preferably, the device also includes a heat recovery and energy-saving module, which comprises a plate heat exchanger and a heat pipe heat exchanger. A fresh air intake duct is installed at the top of the primary water-cutting zone. One side of the plate heat exchanger is connected to an exhaust duct, and the other side is connected to a fresh air intake duct. The evaporation section of the heat pipe heat exchanger is located in the circulating air duct of the secondary drying zone, and the condensation section is located in the air duct that provides regeneration air to the rotary dehumidifier. The tiered heat recovery structure using plate and heat pipe heat exchangers fully utilizes the waste heat from the exhaust in the secondary drying zone, significantly reducing the overall energy consumption of the device and aligning with energy conservation and environmental protection trends. Preheated fresh air entering the primary water-cutting zone improves the water-cutting efficiency of the air knife assembly, and preheated regeneration air entering the rotary dehumidifier enhances the regeneration effect while reducing energy consumption of related components. The heat recovery module has a compact structure and high integration, requiring no significant modifications to the original device structure, facilitating installation and maintenance. Waste heat recovery reduces high-temperature exhaust emissions, minimizing environmental impact, lowering equipment operating costs, and enhancing the device's market competitiveness.

[0017] The beneficial effects of this invention are as follows: The multi-stage drying zone design, through primary water removal, secondary drying, and tertiary curing, ensures that the circuit board can efficiently remove moisture and reach an ideal dry state after cleaning, while avoiding the residual moisture problem that may occur in traditional methods; the air curtain isolation device effectively separates different drying zones, preventing cross-contamination of moisture and ensuring the independence of the working environment of each zone, thereby improving drying efficiency and quality; the integrated sensor array and moisture content detection module enable real-time monitoring and adjustment of temperature and humidity during the drying process, improving the consistency and reliability of drying; the micro-displacement sensor allows for flexible adjustment of the air outlet slit width according to actual needs, enhancing the applicability and flexibility of the equipment; the adjustable design of the internal guide vanes allows for optimized settings according to different working conditions, improving airflow efficiency and uniformity; thus achieving the goal of good drying effect and energy efficiency. Attached Figure Description

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a side view of the air knife assembly; Figure 3 A schematic diagram of installing guide vanes in a vortex duct; Figure 4 This is a schematic diagram of the guide vane structure; Figure 5 This is a schematic diagram of the structure of a porous flow equalizer; Figure 6 A schematic diagram showing the connections between the various components of the conveying mechanism; Figure 7 This is a schematic diagram showing the locations of sensors, heat recovery, and energy-saving modules in each drying zone.

[0019] The components include: 1. Drying chamber; 11. Feed inlet; 12. Discharge outlet; 13. Air curtain isolation device; 2. Primary water cutting zone; 21. Air knife assembly; 211. Air knife body; 212. High-pressure air flow channel; 213. Air outlet slit; 214. Micro electric adjustment mechanism; 215. Micro displacement sensor; 216. Reference cutting edge; 217. Slit adjustment module; 22. High-pressure centrifugal fan; 23. Air filter pressure reducing valve; 24. Fresh air intake duct; 3. Secondary drying zone; 31. Condensation dehumidification module; 32. Centrifugal circulating fan; 33. Medium-temperature heater; 34. Vortex air duct; 341. Guide vane; 342. Short shaft; 343. Driven synchronous pulley; 344. Common adjustment shaft; 345. Motor; 346. Composite sealing adjustment sleeve. 347. Active Synchronizing Wheel, 35. Fresh Air Regulating Valve, 36. Exhaust Pipe, 37. Exhaust Regulating Valve, 38. Bearing Housing, 4. Three-Stage Curing Zone, 41. Laminar Flow Air Supply Unit, 42. Rotary Dehumidifier, 421. Regenerative Heater, 43. Static Eliminator, 44. Static Pressure Chamber, 45. Porous Flow Equalizing Plate, 5. Sensor Array, 6. Moisture Content Detection Module, 7. Electrical Control Cabinet, 71. Main Controller, 8. Conveying Mechanism, 81. Frame, 82. Drive Unit, 83. Servo Motor, 84. Ball Screw Pair, 85. Movable Support, 86. Ceramic Air Flotation Plate, 87. Air Path, 88. Flexible Edge Clamping Wheel, 9. Heat Recovery and Energy Saving Module, 91. Air Plate Heat Exchanger, 92. Heat Pipe Heat Exchanger, 921. Evaporation Section, 922. Condensation Section. Detailed Implementation

[0020] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to the embodiments.

[0021] In the description of this invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer" and "vertical" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; or they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] Furthermore, in the description of this invention, unless otherwise stated, "multiple", "multiple groups", and "multiple roots" mean two or more.

[0024] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments; like Figure 1 As shown, the multi-stage drying and temperature / humidity adaptive device for circuit board cleaning includes a horizontally arranged sealed drying chamber 1. The drying chamber 1 has a feed inlet 11 and a discharge outlet 12 at its front and rear ends, respectively. A conveying mechanism 8 is installed inside the drying chamber 1, and the two ends of the conveying mechanism 8 extend to the feed inlet 11 and the discharge outlet 12 outside the drying chamber 1, respectively. The interior of the drying chamber 1 is divided into a primary water-cutting zone 2, a secondary drying zone 3 and a tertiary curing zone 4 along the conveying direction of the conveying mechanism 8, forming a multi-level drying zone. Adjacent drying zones are separated by an air curtain isolation device 13 installed inside the drying chamber 1. It also includes a sensor array 5 installed on the side walls of each drying zone of the drying chamber 1, a moisture content detection module 6 installed in the secondary drying zone 3, and an electrical control cabinet 7 installed at the bottom of the drying chamber 1. The electrical control cabinet 7 integrates a main controller 71. The sensor array 5 and the moisture content detection module 6 are connected to the main controller 71 by signal. The main controller 71 is connected to the actuators of each multi-stage drying unit for control, and together they constitute a temperature and humidity adaptive control system.

[0025] like Figure 1 and Figure 2 As shown, the primary water-cutting zone 2 includes an external high-pressure centrifugal fan 22, an air filter pressure reducing valve 23 installed in the drying chamber 1, and multiple sets of air knife assemblies 21 installed in an alternating manner. The multiple sets of air knives are arranged along the conveying direction and connected to the air filter pressure reducing valve 23. The air knife assembly 21 includes an air knife body 211, which has a high-pressure air flow channel 212 and an air outlet slit 213. A micro electric adjustment mechanism 214 is installed on the side of the air knife body 211. The actuator of the micro electric adjustment mechanism 214 is connected to a cutting edge of the air outlet slit 213 for driving the cutting edge to move to adjust the slit width. A micro displacement sensor 215 is also installed on the air knife body 211. The detection end of the micro displacement sensor 215 is aligned with the movable cutting edge of the air outlet slit 213 for real-time monitoring of the slit width.

[0026] A replaceable slit adjustment module 217 is installed on the air knife body 211. The slit adjustment module 217 has a reference cutting edge 216, which cooperates with the corresponding cutting edge of the air knife body 211 to form an air outlet slit 213.

[0027] like Figure 1 and Figure 3 As shown, the secondary drying zone 3 includes: The condensation dehumidification module 31 has its air inlet connected to the return air outlet of the secondary drying zone 3; The centrifugal circulating fan 32 has its air inlet connected to the air outlet of the condensation dehumidification module 31; A medium-temperature heater 33 is installed at the air outlet of the centrifugal circulating fan 32; The spiral gradually expanding vortex air duct 34 has its inlet connected to the air outlet of the medium temperature heater 33, and its outlet is a slotted opening facing the conveying mechanism 8. The housing of the vortex duct 34 is also equipped with a fresh air regulating valve 35, an exhaust pipe 36, and an exhaust regulating valve 37.

[0028] Multiple angle-adjustable guide vanes 341 are installed inside the vortex duct 34 near the outlet end. Each guide vane 341 has a short shaft 342 fixedly connected to both ends. A bearing seat 38 is installed on the outside of the vortex duct 34. The short shaft 342 is rotatably connected to the bearing seat 38. The short shaft 342 at one end of the guide vane 341 extends to the outside of the vortex duct 344, and a driven synchronous pulley 343 is fixed at the extended end. A common adjusting shaft 344 and a motor 345 are installed on the outside of the vortex duct 344. An active synchronous pulley 347 corresponding to the position of each driven synchronous pulley 343 is fixed on the common adjusting shaft 344. Each active synchronous pulley 347 is connected to the driven synchronous pulley 343 through a synchronous transmission component.

[0029] like Figure 3 and Figure 4 As shown, the short shaft 342 is connected to a composite sealing adjustment sleeve 346 at the part where it passes through the bearing housing 38, and the main body of the guide vane 341 is a hollow airfoil structure, the cavity of which constitutes an airflow channel.

[0030] like Figure 1 As shown, the three-stage curing zone 4 includes a laminar flow fan unit 41, a rotary dehumidifier 42, and an electrostatic eliminator 43. The laminar flow fan unit 41 is installed on the inner top of the drying chamber 1, and the rotary dehumidifier 42 is installed on the outer top of the drying chamber 1. The air inlet of the laminar flow fan unit 41 is connected to the processing air duct outlet of the rotary dehumidifier 42, and the air outlet is connected downwards to the static pressure chamber 44. Figure 5 As shown, a porous flow equalization plate 45 is installed at the bottom of the static pressure chamber 44, and an electrostatic eliminator 43 is installed inside the discharge port 12 at the end of the three-stage curing zone 4.

[0031] The regeneration duct of the rotary dehumidifier 42 is connected to a regeneration heater 421, and the heat source of the regeneration duct is drawn from the exhaust waste heat recovery circuit of the secondary drying zone 3.

[0032] like Figure 6 As shown, the conveying mechanism 8 includes: The frame 81 is fixedly installed on the base of the drying chamber 1; The drive unit 82 and the conveyor belt driven by the drive unit are tensioned on the frame 81; The width adjustment mechanism is integrated on the frame 81 and includes two sets of symmetrically arranged ball screw pairs 84 driven by servo motors 83. Each ball screw pair 84 is connected to a movable bracket 85 for clamping the side belt of the conveyor belt. The thickness adaptive support mechanism includes a ceramic air flotation plate 86 with micropores and an elastic edge clamping wheel 88 installed on the side of a movable support 85. An air passage 87 with independently adjustable air pressure is connected below the ceramic air flotation plate 86. The ceramic air flotation plate 86 is installed directly below the conveyor belt.

[0033] like Figure 7 As shown, it also includes a heat recovery and energy-saving module 9, which includes a plate heat exchanger 91 and a heat pipe heat exchanger 92. A fresh air intake pipe 24 is installed on the top of the primary water-cutting zone 2. One side of the plate heat exchanger 91 is connected to the exhaust pipe 36, and the other side is connected to the fresh air intake pipe 24. The evaporation section 921 of the heat pipe heat exchanger 92 is set in the circulation duct of the secondary drying zone 3, and the condensation section 922 is set in the duct where the rotary dehumidifier 42 provides regenerated air.

[0034] An embodiment of the present invention: After cleaning, the circuit boards are fed into the sealed drying chamber 1 through the feed inlet 11 by the conveyor mechanism 8. Through the coordinated action of the frame 81, drive unit 82, conveyor belt, width adjustment mechanism, and thickness adaptive support mechanism, stable and precise conveying of the circuit boards is achieved, adapting to circuit boards of different specifications (different widths and thicknesses). The width adjustment mechanism uses a ball screw pair 84 driven by a servo motor 83 to achieve precise and stable adjustment of the conveyor belt width. Symmetrically arranged movable supports 85 can simultaneously clamp the conveyor belt sidewalls, ensuring that the conveyor belt remains flat after width adjustment and preventing conveyor belt slippage. Offset and wrinkles are prevented, ensuring smooth circuit board transport. The ceramic air-floating plate 86 of the thickness-adaptive support mechanism sprays air through micro-holes to form air-floating support, which can avoid direct contact between the circuit board and the support structure, preventing scratches and damage to the circuit board surface. It can also adapt to circuit boards of different thicknesses. The elastic edge clamping wheel 88 can elastically clamp the edge of the circuit board to prevent the circuit board from shifting or shaking during transport, improving transport stability. The independent adjustable air passage 87 below the ceramic air-floating plate 86 can adjust the air-floating pressure according to the thickness and weight of the circuit board to ensure stable support and prevent circuit board deformation.

[0035] Passing through sequentially along the conveying direction of conveyor mechanism 8: Primary Water Cutting Zone 2: When Primary Water Cutting Zone 2 is in operation, the high-pressure centrifugal fan 22 starts, drawing in and pressurizing outside air. The pressurized air is filtered for impurities by the air filter pressure reducing valve 23 and adjusted to the preset pressure before being delivered to multiple sets of staggered air knife assemblies 21. The high-pressure air flow channel 212 inside the air knife body 211 guides the high-pressure air to the air outlet slit 213, forming a high-speed airflow. The staggered air knives can blow airflow from multiple directions (up, down, left, and right) on the circuit board, quickly stripping away free moisture from the circuit board surface and achieving initial water cutting. When adjustment is needed... When the width of the air outlet slit 213 is adjusted, the main controller 71 sends a control signal to the micro electric adjustment mechanism 214. The actuator of the micro electric adjustment mechanism 214 drives the movable blade of the air outlet slit 213 to move. At the same time, the micro displacement sensor 215 detects the displacement data of the movable blade in real time and feeds the data back to the main controller 71. The main controller 71 adjusts the action of the micro electric adjustment mechanism 214 according to the difference between the feedback data and the preset slit width parameter until the width of the air outlet slit 213 reaches the preset value, so as to achieve precise and stable adjustment of the slit width and ensure that the water cutting effect meets the requirements.

[0036] Secondary Drying Zone 3: When the secondary drying zone 3 is in operation, the centrifugal circulating fan 32 starts, drawing in the return air from the secondary drying zone 3. The return air first enters the condensation and dehumidification module 31, which cools and dehumidifies the return air, removing moisture to obtain dry return air. The dry return air then enters the centrifugal circulating fan 32, and after being pressurized by the fan, it is sent to the medium-temperature heater 33. The medium-temperature heater 33 heats the dry return air to a preset temperature (within the medium temperature range to avoid damaging the circuit board). The heated dry airflow then enters the spiral gradually expanding vortex duct 34, forming a stable airflow within the vortex duct 34. The vortex airflow is evenly blown onto the circuit board on the conveying mechanism 8 through the slotted outlet, evaporating and removing residual moisture on and inside the circuit board. At the same time, based on the temperature and humidity detection data of the secondary drying zone 3, the main controller 71 controls the fresh air regulating valve 35 to open, supplementing an appropriate amount of fresh air, and simultaneously controls the exhaust regulating valve 37 to open, expelling the moisture in the cavity through the exhaust pipe 36, maintaining the temperature and humidity of the secondary drying zone 3 within the preset range. The moisture removed by the condensation dehumidification module 31 is discharged through a dedicated pipeline, ensuring that the drying process continues stably and achieving deep drying of the circuit board.

[0037] Three-stage curing zone 4: When the three-stage curing zone 4 is working, the rotary dehumidifier 42 starts to deeply dehumidify the airflow entering the laminar flow fan unit 41, removing trace amounts of moisture from the airflow to obtain low-humidity dry airflow. The laminar flow fan unit 41 draws in the low-humidity dry airflow, pressurizes it, and sends it into the static pressure chamber 44. The static pressure chamber 44 stabilizes and evenly distributes the airflow, which is then blown vertically onto the circuit board on the conveying mechanism 8 through the porous flow equalization plate 45, forming a stable laminar flow airflow for final curing and drying of the circuit board, thoroughly removing any residual trace amounts of moisture. When the circuit board moves to the end of the three-stage curing zone 4 on the conveying mechanism 8, the electrostatic eliminator 43 inside the discharge port 12 starts to release positive and negative ions, neutralizing the static electricity generated on the surface of the circuit board due to airflow friction and removing the static charge from the surface of the circuit board. After curing, drying, and electrostatic elimination, the circuit board is sent out through the discharge port 12, completing the entire drying process and ensuring that the moisture content and static electricity index of the circuit board meet the requirements. When the rotary dehumidifier 42 is working, the air in the regeneration duct needs to be heated to regenerate the rotor (i.e., remove the moisture adsorbed by the rotor). When the exhaust from the secondary drying zone 3 is discharged through the exhaust pipe 36, the air in the regeneration duct is heated according to the temperature requirements of the regeneration air, in conjunction with the waste heat of the exhaust, so that the regeneration air reaches the preset regeneration temperature. The heated regeneration air flows through the regeneration area of ​​the rotary dehumidifier 42, carrying away a large amount of waste heat adsorbed by the rotor. This part of the exhaust is introduced into the regeneration duct of the rotary dehumidifier 42 through the waste heat recovery circuit. The moisture adsorbed by the regeneration heater 421 is removed, and the rotor is regenerated. The regenerated air is discharged through a dedicated pipe.

[0038] The air curtain isolation device 13 forms an air curtain between adjacent drying zones, blocking the airflow between different areas and avoiding mutual interference between airflows with different humidity and temperature, thus ensuring a stable temperature and humidity environment in each area. The sensor array 5 collects temperature and humidity data of each drying zone in real time, and the moisture content detection module 6 accurately detects the moisture content of the circuit board in the secondary drying zone 3. All of the above data are transmitted to the main controller 71 in the electrical control cabinet 7. The main controller 71 analyzes and processes the data, and according to the preset drying parameters and real-time detection data, it controls the actuators (such as fans, heaters, dehumidification components, etc.) of the primary water-cutting zone 2, the secondary drying zone 3, and the tertiary curing zone 4 in real time, dynamically adjusting the airflow intensity, temperature, and humidity of each area to achieve adaptive temperature and humidity control, ensuring that the circuit board is in the optimal environment at each drying stage, and finally being sent out through the discharge port 12 to complete the drying operation.

[0039] When the heat recovery and energy-saving module 9 is working, it consists of two waste heat recovery loops: the first loop is a fresh air preheating loop, where the fresh air intake pipe 24 of the first-stage water-cutting zone 2 introduces fresh air from the outside, and the exhaust pipe 36 discharges the waste gas (containing a large amount of waste heat) from the equipment. The fresh air and waste gas flow through both sides of the plate heat exchanger 91, where they exchange heat. The waste heat of the waste gas is transferred to the fresh air to preheat it. The preheated fresh air then enters the first-stage water-cutting zone 2 to help improve the water-cutting effect and reduce temperature loss inside the equipment; the second loop is a regeneration air... In the gas heating circuit, the evaporation section 921 of the heat pipe heat exchanger 92 is located in the circulating air duct of the secondary drying zone 3, absorbing the waste heat in the circulating airflow of the secondary drying zone 3 to evaporate the working fluid in the heat pipe; the evaporated working fluid flows to the condensation section 922 located in the regeneration air duct of the rotary dehumidifier 42, releasing the absorbed waste heat into the air in the regeneration air duct to provide auxiliary heating for the regeneration air; the preheated regeneration air is further heated by the regeneration heater 421 (or no heating is required if there is sufficient waste heat), and then enters the rotary dehumidifier 42 to achieve rotary regeneration.

[0040] Before starting the equipment, the drying parameters are set through the main controller 71 in the electrical control cabinet 7: the outlet air pressure of the first-stage water-cutting zone 2 is 0.3MPa, the width of the outlet slit 213 is 0.5mm, and the conveying speed is 0.3m / s; the temperature of the second-stage drying zone 3 is 65℃, the humidity is 30%RH, and the airflow speed is 2m / s; the temperature of the third-stage curing zone 4 is 70℃, the humidity is 20%RH, and the laminar flow speed is 1.5m / s; the preset value for the circuit board moisture content is ≤0.1%.

[0041] After cleaning, the circuit board is placed on the conveyor belt of the conveying mechanism 8 through the feed port 11. The drive unit 82 is started, and the conveyor belt is driven to run at a constant speed to send the circuit board into the drying chamber 1.

[0042] Operation of the first-stage water-cutting zone 2: The high-pressure centrifugal fan 22 starts, drawing in and pressurizing outside air. After impurities are filtered by the air filter pressure reducing valve 23 and adjusted to 0.3MPa, the air is delivered to the staggered air knife assembly 21. The high-pressure air is guided through the high-pressure air flow channel 212 of the air knife body 211 to the air outlet slit 213, forming a high-speed airflow that blows from multiple directions (up, down, left, and right) on the circuit board, quickly removing free moisture from the surface of the circuit board. The micro-displacement sensor 215 monitors the width of the air outlet slit 213 in real time. If a deviation occurs, the main controller 71 controls the micro electric adjustment mechanism 214 to adjust the blade position to ensure a stable slit width. At the same time, the fresh air intake pipe 24 introduces outside fresh air, which is preheated by the waste heat of the exhaust gas in the air plate heat exchanger 91 before entering the first-stage water-cutting zone 2 to further enhance the water-cutting effect.

[0043] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications and equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A multi-stage drying and temperature / humidity adaptive device for circuit board cleaning, comprising a laterally arranged sealed drying chamber (1), characterized in that, The drying chamber (1) has an inlet (11) and an outlet (12) at its front and rear ends, respectively. A conveying mechanism (8) is installed inside the drying chamber (1), and the two ends of the conveying mechanism (8) extend to the inlet (11) and outlet (12) outside the drying chamber (1), respectively. The interior of the drying chamber (1) is divided into a primary water-cutting zone (2), a secondary drying zone (3) and a tertiary curing zone (4) along the conveying direction of the conveying mechanism (8), forming a multi-level drying zone. Adjacent drying zones are separated by an air curtain isolation device (13) installed inside the drying chamber (1). It also includes a sensor array (5) set on the side wall of each drying zone of the drying chamber (1), a moisture content detection module (6) set in the secondary drying zone (3) and an electrical control cabinet (7) set at the bottom of the drying chamber (1). The electrical control cabinet (7) integrates a main controller (71). The sensor array (5), the moisture content detection module (6) and the main controller (71) are connected by signal. The main controller (71) is connected to the actuators of the multi-stage drying unit and together constitutes a temperature and humidity adaptive control system.

2. The multi-stage drying and temperature / humidity adaptive device for circuit board cleaning according to claim 1, characterized in that, The primary water-cutting zone (2) includes an external high-pressure centrifugal fan (22), an air filter pressure reducing valve (23) installed in the drying chamber (1), and multiple sets of air knife assemblies (21) installed in an alternating manner. The multiple sets of air knives are arranged along the conveying direction and connected to the air filter pressure reducing valve (23). The air knife assembly (21) includes an air knife body (211). The air knife body (211) has a high-pressure air flow channel (212) and an air outlet slit (213). A micro electric adjustment mechanism (214) is installed on the side of the air knife body (211). The actuator of the micro electric adjustment mechanism (214) is connected to a cutting edge of the air outlet slit (213) for driving the cutting edge to move to adjust the slit width. A micro displacement sensor (215) is also installed on the air knife body (211). The detection end of the micro displacement sensor (215) is aligned with the movable cutting edge of the air outlet slit (213) for real-time monitoring of the slit width.

3. The multi-stage drying and temperature / humidity adaptive device for circuit board cleaning according to claim 2, characterized in that, The air knife body (211) is equipped with a replaceable slit adjustment module (217), which has a reference cutting edge (216). The reference cutting edge (216) cooperates with the corresponding cutting edge of the air knife body (211) to form an air outlet slit (213).

4. The multi-stage drying and temperature / humidity adaptive device for circuit board cleaning according to claim 1, characterized in that, The secondary drying zone (3) includes: The condensation dehumidification module (31) has its air inlet connected to the return air outlet of the secondary drying zone (3); Centrifugal circulating fan (32), whose air inlet is connected to the air outlet of condensation dehumidification module (31); A medium-temperature heater (33) is installed at the air outlet of a centrifugal circulating fan (32); The spiral gradually expanding vortex air duct (34) has its inlet connected to the air outlet of the medium temperature heater (33) and its outlet is a slotted opening facing the conveying mechanism (8). The vortex duct (34) is also equipped with a fresh air regulating valve (35), an exhaust pipe (36), and an exhaust regulating valve (37).

5. The multi-stage drying and temperature / humidity adaptive device for circuit board cleaning according to claim 4, characterized in that, The vortex duct (34) has multiple angle-adjustable guide vanes (341) installed inside near the outlet end. Each guide vane (341) has a short shaft (342) fixedly connected to both ends. The vortex duct (34) has a bearing seat (38) installed on the outside. The short shaft (342) is rotatably connected to the bearing seat (38). The short shaft (342) at one end of the guide vane (341) extends to the outside of the vortex duct (34), and a driven synchronous wheel (343) is fixed at the extended end. A common adjusting shaft (344) and a motor (345) are installed on the outside of the vortex duct (34). An active synchronous wheel (347) corresponding to the position of each driven synchronous wheel (343) is fixed on the common adjusting shaft (344). Each active synchronous wheel (347) is connected to the driven synchronous wheel (343) through a synchronous transmission component.

6. The multi-stage drying and temperature / humidity adaptive device for circuit board cleaning according to claim 5, characterized in that, The short shaft (342) is connected to a composite sealing adjustment sleeve (346) at the part where it passes through the bearing seat (38). The main body of the guide vane (341) is a hollow airfoil structure, and its cavity forms an airflow channel.

7. The multi-stage drying and temperature / humidity adaptive device for circuit board cleaning according to claim 1, characterized in that, The three-stage curing zone (4) includes a laminar flow fan unit (41), a rotary dehumidifier (42), and an electrostatic eliminator (43). The laminar flow fan unit (41) is installed on the top inner side of the drying chamber (1), and the rotary dehumidifier (42) is installed on the top outer side of the drying chamber (1). The air inlet of the laminar flow fan unit (41) is connected to the processing air duct outlet of the rotary dehumidifier (42), and the air outlet is connected downward to a static pressure chamber (44). A perforated flow equalization plate (45) is installed at the bottom of the static pressure chamber (44), and the electrostatic eliminator (43) is installed inside the discharge port (12) at the end of the three-stage curing zone (4).

8. The multi-stage drying and temperature / humidity adaptive device for circuit board cleaning according to claim 7, characterized in that, The regeneration duct of the rotary dehumidifier (42) is connected to a regeneration heater (421), and the heat source of the regeneration duct is drawn from the exhaust waste heat recovery circuit of the secondary drying zone (3).

9. The multi-stage drying and temperature / humidity adaptive device for circuit board cleaning according to claim 1, characterized in that, The transmission mechanism (8) includes: The frame (81) is fixedly installed on the base of the drying chamber (1); A drive unit (82) and a conveyor belt driven by the drive unit, the conveyor belt being tensioned on a frame (81); The width adjustment mechanism is integrated on the frame (81) and includes two sets of symmetrically arranged ball screw pairs (84) driven by servo motors (83). Each ball screw pair (84) is connected to a movable bracket (85) for clamping the side belt of the conveyor belt. The thickness adaptive support mechanism includes a ceramic air flotation plate (86) with micropores and an elastic edge clamping wheel (88) installed on the side of a movable support (85). The ceramic air flotation plate (86) is connected to an air passage (87) with independent air pressure adjustment below it. The ceramic air flotation plate (86) is installed directly below the conveyor belt.

10. The multi-stage drying and temperature / humidity adaptive device for circuit board cleaning according to claim 1, characterized in that, It also includes a heat recovery and energy saving module (9), which includes a plate heat exchanger (91) and a heat pipe heat exchanger (92). A fresh air intake pipe (24) is installed on the top of the primary water cutting zone (2). One side of the plate heat exchanger (91) is connected to an exhaust pipe (36), and the other side is connected to a fresh air intake pipe (24). The evaporation section (921) of the heat pipe heat exchanger (92) is located in the circulation duct of the secondary drying zone (3), and the condensation section (922) is located in the duct that provides regenerated air to the rotary dehumidifier (42).

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