Vertical spray etching system and production line of printed circuit board

Abstract

The invention relates to a vertical spraying etching system and a production line of a printed circuit board, the system comprises two spraying units which are oppositely arranged to form a spraying channel, each spraying unit comprises a spraying frame fixing main body and U-shaped groove spraying frame guide rails which are respectively arranged on the spraying frame fixing main body, and the system also comprises a spraying module and a spraying pipe driving mechanism, the spraying module is arranged on the U-shaped groove spraying frame guide rail in a sliding mode, the spraying module comprises a plurality of spraying pipe combinations arranged in the vertical direction, and the number of nozzles contained in the spraying pipe combinations is reduced one by one in the direction from the top to the bottom; the spray pipe driving mechanism comprises an elliptical roller driven by the main shaft and a spray frame lifting connecting rod, two ends of the spray frame lifting connecting rod are eccentrically connected with the elliptical roller, and the middle part is connected with the spray module to drive the spray module to swing up and down. The invention provides a vertical spray etching system of a printed circuit board and a production line, and aims to improve the spray uniformity and reduce the residual liquid medicine so as to facilitate the improvement of the etching quality of a precise circuit.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board (PCB) manufacturing equipment technology, and more specifically to a spray system for PCB developing and etching processes and a production line including the system. Background Technology

[0002] In the manufacturing process of printed circuit boards (PCBs), development and etching are crucial steps in forming precision circuitry. Currently, the industry commonly uses horizontal spray equipment, where the board to be processed passes horizontally and the spray solution is sprayed from top to bottom. This configuration is sufficient for processing circuits with large line widths and spacings, but it is gradually showing some shortcomings when facing the fabrication of more precise circuits. Because the board surface is horizontal, the spray solution tends to remain and accumulate on the board surface due to gravity, forming the so-called "pool effect." Even with auxiliary liquid extraction devices, it is difficult to completely eliminate this localized liquid accumulation on the board surface. Liquid accumulation leads to differences in the contact time and concentration of the etching solution between different areas of the board surface, thus affecting the etching uniformity and potentially causing defects such as excessively thin lines and burrs, thus hindering the improvement of the yield of precision circuit products. Some improved designs have attempted to adopt a vertical layout, but there is still room for further optimization in terms of how to achieve efficient and uniform dynamic spraying and how to facilitate maintenance. Summary of the Invention

[0003] In view of this, the present invention provides a vertical spray etching system and production line for printed circuit boards, which aims to improve spray uniformity and reduce chemical residue, thereby improving the etching quality of precision circuits.

[0004] The objective of this invention is achieved through the following technical solution: A vertical spray etching system for printed circuit boards includes a first spray unit and a second spray unit with identical structural components, arranged opposite each other to form a spray channel. Both the first and second spray units include a spray frame fixing body and U-shaped slot spray frame guide rails respectively disposed on the spray frame fixing body. They also include a spray module and a spray nozzle driving mechanism. The spray module is slidably disposed on the U-shaped slot spray frame guide rail. The spray module includes multiple spray nozzle combinations arranged vertically, with the number of nozzles in each spray nozzle combination decreasing sequentially from top to bottom. The spray nozzle driving mechanism is eccentrically connected to both ends of a spray frame lifting linkage via elliptical rollers disposed on a drive shaft, converting the rotational motion of the drive shaft into linear reciprocating motion in the middle of the spray frame lifting linkage, thereby driving the spray module to swing.

[0005] The system's core architecture, consisting of vertical spraying, gradient nozzles, and dynamic oscillation, was established. The opposing spray frame guides the circuit board vertically, utilizing gravity to promote liquid flow and laying the structural foundation for eliminating the pooling effect. Multiple vertically arranged spray modules, with the number of nozzles decreasing from top to bottom, adapt to the time difference in liquid reception in different areas of the board surface during vertical movement, resulting in more even spray coverage. The reciprocating oscillation of the nozzles causes the etching liquid flow to periodically scan the board surface, dynamically changing the liquid flow impact angle and thus avoiding the uneven coverage that may occur with fixed-point spraying. A drive mechanism composed of an eccentric connecting rod and elliptical rollers reliably converts rotational motion into regular oscillation. These features work together to solve the problem of uniformity in horizontal spraying.

[0006] Preferably, the spray module includes a first spray pipe assembly, a second spray pipe assembly, a third spray pipe assembly, and a fourth spray pipe assembly arranged from top to bottom, and the nozzles on each spray pipe assembly are staggered, with the number of nozzles gradually decreasing from top to bottom.

[0007] Four nozzle combinations were defined, with their nozzles arranged in a staggered pattern and their number decreasing progressively. These four structures provide a precise gradient adjustment unit. The staggered arrangement avoids overlapping projections of the upper and lower nozzles, reducing uneven linear spraying. The decreasing number of nozzles from top to bottom provides refined compensation for the liquid reception time at different passage points on the plate, making the spray density more aligned with actual needs. This optimizes the spray uniformity in the vertical direction in terms of both distribution density and spatial location.

[0008] Preferably, the U-shaped groove spray frame guide rail is provided with guide rail pulleys inside to reduce sliding resistance and is reinforced by U-shaped groove guide rail fixing buckles. The spray module has V-shaped guide surfaces on both sides that cooperate with the guide rail pulleys. The spray pipe drive mechanism also includes a transmission main shaft driven by a main transmission motor and belt, and elliptical rollers are set on the transmission main shaft.

[0009] The guide rail pulleys convert sliding friction into rolling friction, reducing the oscillation resistance of the spray module, making operation smoother and more stable, and reducing the risk of wear and jamming. The fixing buckles enhance the rigidity of the guide rail, ensuring precise sliding trajectory. The elliptical rollers are integrated into the transmission spindle driven by the main motor, forming a centralized power source. Belt drive enables synchronous and unified driving of the oscillation of multiple nozzles, simplifying the structure and ensuring consistent operation.

[0010] Preferably, the main transmission motor and belt are provided with a transmission motor protective cover; a transmission roller is installed on the transmission main shaft, and the main transmission motor and belt drive the transmission roller and transmission main shaft to rotate through the V-shaped transmission belt.

[0011] The protective cover effectively isolates corrosive liquids and dust from eroding the core drive components, improving environmental resistance and service life. Utilizing a V-belt drive, which takes advantage of its wedge friction principle, it provides a larger transmission contact surface and anti-slip capability, resulting in higher transmission efficiency and more stable operation. This ensures sufficient power to drive the spray module to overcome resistance and oscillate stably.

[0012] Preferably, the spray module is fixedly connected to the spray frame lifting linkage via spray pipe connecting screws.

[0013] The screw connection provides a robust and reliable removable fixing method. Strong thread preload ensures the connection remains secure during oscillation, guaranteeing precise motion transmission. Its removability simplifies and expedites maintenance, cleaning, or replacement of the spray module, enabling modular maintenance, reducing downtime, and improving equipment maintainability.

[0014] Preferably, the first nozzle assembly, the second nozzle assembly, the third nozzle assembly, and the fourth nozzle assembly are each supplied with etching solution through independent etching solution supply pipes, and each etching solution supply pipe is equipped with a control valve and an automatic pressure regulating device.

[0015] Independent liquid supply pipes and control units enable precise and independent adjustment of the spray parameters for each nozzle combination. Control valves facilitate on / off control, while automatic pressure regulation devices stably maintain preset pressure. This allows operators to fine-tune the impact force of sprays in different upper and lower areas according to the gradient spray design, thereby optimizing the etching uniformity in the vertical direction and enhancing process adaptability.

[0016] Preferably, the etching solution supply pipe and the nozzle assembly are connected by a flexible transparent telescopic sleeve.

[0017] The flexible, transparent telescopic sleeve solves the motion compensation problem between nozzle oscillation and fixed piping. Its flexibility and telescopic properties can adapt to displacement changes at the connection end, avoiding pipe kinking or stress damage. The transparent material allows for direct observation of the internal fluid flow, which is beneficial for daily monitoring and troubleshooting, balancing dynamic sealing reliability with ease of maintenance.

[0018] Preferably, the nozzles in the first nozzle assembly, second nozzle assembly, third nozzle assembly and fourth nozzle assembly have the same nozzle length, and the distance between the nozzles on the nozzle increases progressively from top to bottom.

[0019] Equal-length nozzles facilitate manufacturing and interchangeability. The nozzle spacing increases progressively from top to bottom, a specific implementation method that synergizes with the decreasing number of nozzles. This regularized spacing design ensures uniform coverage of each layer of nozzles in the horizontal direction, while the regular spacing variation between layers achieves a smooth gradient transition of spray intensity in the vertical direction, refining uniformity control.

[0020] Preferably, the V-shaped conveyor belt is made of acid and alkali resistant rubber material; the size of the elliptical rollers can be customized according to the swing amplitude.

[0021] Acid and alkali resistant rubber belts resist chemical corrosion, ensuring the durability of transmission components in harsh environments. Customizable elliptical roller sizes allow for adjustment of the spray module's oscillation amplitude by changing the rollers, thus flexibly adapting to different plate heights, process precision requirements, or spray patterns, enhancing the equipment's adaptability to various production needs.

[0022] A printed circuit board production line includes at least one vertical spray etching system as described above, and the conveying device of the production line is configured to drive the printed circuit board vertically through a spray channel formed by two systems arranged opposite each other.

[0023] This design protects the complete production line solution integrating the spray system. It defines the specific application scenario for the system to achieve vertical spraying on the production line, namely, working in conjunction with a vertical conveyor to allow circuit boards to pass vertically through the spray channel. This integration achieves the fusion of advanced etching processes with existing manufacturing workflows, directly leveraging the system to improve etching uniformity and fine circuit fabrication capabilities, thereby enhancing the overall yield and technical level of the production line.

[0024] The advantages of this invention compared to the prior art are: The vertical spray etching system and production line for printed circuit boards of the present invention utilizes a vertically sprayed channel formed by relatively arranged spray frames to guide the circuit board through vertically. This facilitates smoother flow of the etching solution away from the board surface under gravity, providing a different structural approach to reduce liquid accumulation on the board. The gradient design of the spray modules arranged vertically with the number of nozzles decreasing from top to bottom matches the differences in liquid reception time in different areas during the vertical movement of the board surface, promoting balanced spray coverage across the entire board. Simultaneously, the dynamic spraying method of the spray modules oscillating up and down along the guide rail changes the fixed-angle spraying pattern, allowing the solution flow to periodically sweep across the board surface. This helps break the fixed liquid flow distribution, improves the uniformity of spray coverage, and reduces localized etching unevenness that may occur with static spraying. The drive mechanism composed of elliptical rollers and eccentric connecting rods provides a reliable and easily implemented power conversion method for this regular oscillation. In summary, the combination of the above features works together to improve etching uniformity, which is of positive significance for improving the yield of fine circuit fabrication. In addition, the modular connection and independent pressure regulation design involved in the system also bring convenience to the operation, maintenance and process adjustment of the equipment. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the overall structure of a vertical spray etching system for a printed circuit board according to an embodiment of the present invention.

[0027] Figure 2 This is a schematic diagram of the structure of a V-shaped conveyor belt according to an embodiment of the present invention.

[0028] Figure 3 This is a schematic diagram of the structure of an elliptical roller according to an embodiment of the present invention.

[0029] Figure 4 This is a schematic diagram of the structure of a U-shaped spray frame guide rail according to an embodiment of the present invention.

[0030] Labeling Explanation: 1. Spray frame fixing body; 2. Fixing screw; 3. U-shaped groove spray frame guide rail; 31. Guide rail pulley; 32. V-shaped guide surface; 4. U-shaped groove guide rail fixing buckle; 5. First spray pipe assembly; 6. Second spray pipe assembly; 7. Third spray pipe assembly; 8. Fourth spray pipe assembly; 9. Nozzle; 10. Spray pipe connecting screw; 11. Elliptical roller; 12. Spray frame lifting linkage; 13. Conveyor spindle; 14. Conveyor roller; 15. V-shaped conveyor belt; 16. Flexible transparent telescopic sleeve; 17. Automatic pressure adjustment device; 18. Control valve; 19. Etching solution supply pipe; 20. Main conveyor motor and belt; 21. Conveyor motor protective cover. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0033] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of the embodiments of this application, it should be understood that the terms "upper," "lower," "left," "right," "vertical," "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product of this application is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only for the convenience of describing this application 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 limitations on this application.

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0035] The technical solutions in this application will now be described with reference to the accompanying drawings. Example 1

[0036] This embodiment provides a vertical spray etching system for printed circuit boards, including a first spray unit and a second spray unit with identical structural components, arranged opposite each other to form a spray channel. Both the first and second spray units include a spray frame fixing body 1 and U-shaped groove spray frame guide rails 3 respectively disposed on the spray frame fixing body 1. The spray module is slidably mounted on the U-shaped spray frame guide rail 3. The spray module includes multiple spray pipe combinations arranged in the vertical direction, and the number of nozzles contained in each spray pipe combination decreases from top to bottom. The nozzle drive mechanism is designed to reliably convert the rotational motion of the main transmission motor into the regular reciprocating oscillation of the spray module in the vertical direction. This mechanism employs a stable structure with dual-sided drive and central output.

[0037] 1. Power Transmission and Core Conversion Section: The main transmission motor and belt 20 serve as the power source, driving the transmission main shaft 13 to rotate continuously via the V-shaped transmission belt 15. Two elliptical rollers 11, located on either side of the spray module, are fixedly mounted on the transmission main shaft 13. A key improvement is that the two ends of a spray frame lifting linkage 12 are eccentrically connected to the corresponding elliptical rollers 11 via bearings or couplings. The middle section of the spray frame lifting linkage 12 is securely connected to the spray module via a spray pipe connecting screw 10 or a hinge. When the transmission main shaft 13 drives the elliptical rollers 11 to rotate at a constant speed, the two elliptical rollers 11 synchronously push the two ends of the spray frame lifting linkage 12. Due to the eccentric effect, the middle section of the linkage is forced to produce a precise, large-amplitude reciprocating linear motion, thereby directly driving the connected spray module.

[0038] 2. Motion Execution and Optimization: Driven by the reciprocating motion, the spray module moves along a pair of vertically arranged U-shaped spray frame guide rails 3. To optimize motion performance, guide rail pulleys 31 are installed inside the guide rails, which cooperate with the V-shaped guide surfaces 32 on both sides of the spray module to convert sliding friction into rolling friction, making the oscillation more effortless and stable. The size of the elliptical rollers 11 can be customized according to the required oscillation amplitude.

[0039] The advantages of this design are: the two ends of the spray frame lifting linkage 12 are driven synchronously, forming a balanced force system. The driving force transmitted to the middle is direct and without eccentric load, which greatly improves the straightness and stability of the spray module's movement trajectory and avoids jamming or shaking that may occur from unilateral drive. It is particularly suitable for industrial scenarios that require long-term stable operation.

[0040] In this embodiment, the spray module includes a first spray pipe assembly 5, a second spray pipe assembly 6, a third spray pipe assembly 7 and a fourth spray pipe assembly 8 arranged from top to bottom, and the nozzles 9 on each spray pipe assembly are arranged in an alternating manner, with the number of nozzles 9 gradually decreasing from top to bottom.

[0041] The spray module is defined as four specific structures arranged at the top and bottom, with each group of nozzles 9 arranged in a staggered pattern and their number gradually decreasing. The four nozzle combinations provide a sufficient number of independent control units, allowing for more precise adjustment of the longitudinal gradient of the spray intensity. The staggered arrangement of the nozzles 9 effectively avoids complete overlap of the jet streams from adjacent nozzle combinations in spatial projection. This staggered design allows the etching liquid streams sprayed from different heights to cover finer areas on the board surface, reducing linear stripe-like spray unevenness that may occur due to nozzle alignment. The gradual decrease in the number of nozzles provides fine compensation for the difference in liquid reception time across different sections of the board surface during vertical spraying. The upper nozzle combination has more nozzles 9, providing denser spray coverage when passing through the top area of ​​the board surface for a short time; as the board moves downwards and the passage time accumulates, the lower nozzle combination reduces the number of nozzles 9 but still maintains a staggered arrangement, ensuring sufficient coverage while avoiding localized overspray. This combination of "decreasing quantity" and "spatial staggering" optimizes the uniformity of the etching solution distribution on the vertically moving board surface from two dimensions: nozzle distribution density and spatial position.

[0042] In this embodiment, the U-shaped spray frame guide rail 3 is equipped with guide rail pulleys 31 to reduce sliding resistance, and is reinforced by U-shaped guide rail fixing buckles 4. The spray module has V-shaped guide surfaces 32 on both sides that cooperate with the guide rail pulleys 31. The spray pipe drive mechanism also includes a transmission main shaft 13 driven by a main transmission motor and belt 20, with elliptical rollers 11 mounted on the transmission main shaft 13. Specifically, the guide rail pulleys 31 are rotatably mounted at a preset position inside the U-shaped spray frame guide rail 3 via a rotating shaft. When the spray module moves up and down under the drive of the spray frame lifting linkage 12, the V-shaped guide surfaces 32 on both sides of the spray module contact the raceways of one or more guide rail pulleys 31, converting the potential sliding friction into rolling friction. This design not only significantly reduces motion resistance, making the swing smoother and more fluid, but also reduces wear on the contact surfaces of the guide rail and spray frame caused by long-term friction, helping to maintain motion accuracy and system stability during long-term operation. The guide rail pulley 31 can be made of corrosion-resistant engineering plastics or rubber-coated metal to suit wet chemical production environments.

[0043] The motion support and power transmission of the spray module's drive system were optimized by adding guide rail pulleys and fixing buckles. The guide rail pulleys, located inside the U-shaped spray frame guide rail 3, convert the sliding friction between the spray module and the guide rail into rolling friction, significantly reducing the resistance experienced by the spray module during reciprocating oscillations. This improvement results in a smaller drive load, smoother and more stable system operation, and also reduces the risk of wear or jamming of the drive mechanism due to excessive frictional resistance, thus improving long-term operational reliability. The U-shaped guide rail fixing buckle 4 enhances the structural stability of the guide rail, preventing deformation under long-term stress or vibration, ensuring that the spray module always slides precisely along the predetermined trajectory. The elliptical roller 11 is integrated onto the main transmission shaft 13 driven by the main transmission motor and belt 20, forming a centralized and efficient power source. This design utilizes a mature belt drive method to reliably transmit the rotational power of the main transmission motor and belt 20 to the main transmission shaft 13 and elliptical roller 11, achieving synchronous and unified drive of the combined oscillation movements of multiple nozzles. This centralized drive method simplifies the system structure, reduces the complexity and cost of setting separate drivers on multiple nozzles, and ensures the consistency of the oscillation frequency and phase of all nozzle combinations.

[0044] In this embodiment, a protective cover 21 for the main conveyor motor and belt 20 is provided on the outside; a conveyor roller 14 is installed on the main conveyor shaft 13, and the main conveyor motor and belt 20 drive the conveyor roller 14 and the main conveyor shaft 13 to rotate through the V-shaped conveyor belt 15.

[0045] The addition of protective covers and the adoption of specific transmission structures enhance the system's environmental adaptability and transmission reliability. The transmission motor protective cover 21 provides physical isolation protection for the main transmission motor and belt 20, effectively preventing etching solutions, moisture, or dust that may splash in the production environment from directly contacting and corroding the motor and transmission components. This protective measure significantly improves the durability of the core drive unit under harsh operating conditions, reduces the failure rate caused by corrosion or contamination, and ensures the continuity of the production process. The use of a V-shaped transmission belt 15 to drive the transmission rollers 14 mounted on the main transmission shaft 13 utilizes the wedge-shaped friction principle of the V-shaped belt in the pulley groove, providing a larger effective contact area and stronger transmission friction. Compared to flat belts, this transmission method has higher transmission efficiency and stronger anti-slip capability, and is particularly stable during startup or when there are slight fluctuations in load. The power is transmitted from the main motor to the transmission roller 14 and then to the transmission main shaft 13 through the V-shaped transmission belt 15, forming a first-stage reduction and torque increase. This makes the torque that ultimately drives the elliptical roller 11 to rotate more abundant, ensuring that the nozzle assembly has enough power to overcome resistance and operate powerfully and stably.

[0046] In this embodiment, the spray module is fixedly connected to the spray frame lifting link 12 via the spray pipe connecting screw 10.

[0047] The spray module and lifting linkage are detachably fixed using a screw connection. The nozzle connecting screw 10 is a standardized and highly reliable mechanical fastening method. The tightening of the threads generates a strong axial preload, firmly locking the spray module onto the spray frame lifting linkage 12. This ensures that the connection will not loosen or shift relative to the frame during high-speed reciprocating oscillation, thus guaranteeing the accuracy of the spray action transmission. Another significant advantage of this connection method is its detachability. When maintenance is required on the spray module or a specific nozzle assembly within it, operators can easily loosen and remove the nozzle connecting screw 10, separating the entire spray module from the drive linkage for maintenance. This modular design significantly simplifies maintenance operations, reduces downtime, improves equipment maintainability, and facilitates flexible replacement of nozzle assemblies according to different process requirements.

[0048] In this embodiment, the first nozzle assembly 5, the second nozzle assembly 6, the third nozzle assembly 7 and the fourth nozzle assembly 8 are respectively supplied with etching solution through independent etching solution supply pipes 19, and each etching solution supply pipe 19 is equipped with a control valve 18 and an automatic pressure regulating device 17.

[0049] By configuring independent liquid supply lines and control units for each nozzle assembly, precise and independent control of spray parameters in each area is achieved. Independent etching solution supply pipes 19 mean that the liquid flow to each nozzle assembly does not interfere with each other at the source, creating the foundation for differentiated liquid supply. Control valves 18 installed on each supply pipe provide manual or automatic control of the liquid flow, facilitating the targeted closure or opening of specific nozzle assemblies to meet the needs of different sized panels or special process sections. The automatic pressure regulating device 17 is the core of achieving precise process control; it can monitor and automatically adjust the etching solution pressure to the corresponding nozzle assembly in real time, stabilizing it at a preset value. Since nozzle assemblies at different positions have different spray functions, this independent pressure control allows operators to separately set and fine-tune the spray impact force of the upper, middle, and lower zones according to the gradient spray design concept. For example, the upper spray pressure can be appropriately increased to compensate for the shorter spray time, or the lower pressure can be decreased to prevent over-etching, thereby achieving more optimized etching uniformity in the vertical direction and enhancing the adaptability and controllability of the process.

[0050] In this embodiment, the etching solution supply pipe 19 and the nozzle assembly are connected by a flexible transparent telescopic sleeve 16.

[0051] The use of a flexible transparent telescopic sleeve 16 as a connecting component effectively solves the problem of relative motion compensation between the nozzle assembly and the fixed supply pipe during reciprocating oscillation. The flexibility provides the connecting pipe with good bending deformation capability, while the telescopic characteristics allow for a certain degree of elastic change in the length direction. When the nozzle assembly oscillates up and down under the action of the spray frame lifting linkage 12, the flexible transparent telescopic sleeve 16 can bend and extend accordingly, freely adapting to the displacement changes at both ends of the connection, thus avoiding the risks of pipe twisting, stress concentration, or detachment caused by rigid connections. The transparent material allows operators and maintenance personnel to directly observe the flow status of the etching solution inside the pipe, such as whether there are air bubbles, whether it is unobstructed, or whether there are sediments, facilitating condition monitoring and troubleshooting. This connection method not only ensures the sealing reliability and durability of the supply pipe connection under dynamic operating conditions but also provides convenience for daily maintenance and visual inspection.

[0052] In this embodiment, the nozzles in the first nozzle assembly 5, the second nozzle assembly 6, the third nozzle assembly 7 and the fourth nozzle assembly 8 have the same length, and the spacing between the nozzles 9 on the nozzles increases progressively from top to bottom.

[0053] The specifications stipulate that each nozzle assembly uses nozzles of equal length, and clearly define the specific distribution pattern of the nozzle 9 spacing increasing progressively from top to bottom. Using nozzles of the same length simplifies manufacturing and spare parts management, ensures structural consistency among nozzle assemblies, and facilitates installation and interchangeability. The progressively increasing nozzle 9 spacing from top to bottom is a specific implementation method that complements the progressively decreasing number of nozzles 9 from top to bottom. Given a fixed total nozzle length, reducing the number of nozzles 9 naturally leads to an increase in the average spacing. Specifying this spacing change as "progressively increasing" implies that the spacing change is regular and controllable, rather than random. This regularized spacing design, combined with the overall concept of gradient spraying, makes the transition from the densely sprayed area at the top to the sparsely sprayed area at the bottom smoother. It ensures that within the coverage area of ​​each nozzle assembly, the distribution of etching solution in the horizontal direction of the board surface remains relatively uniform. Simultaneously, through the coordinated variation of interlayer spacing and number, it achieves gradient control of spray intensity in the vertical direction of the board surface, further refining the means of uniformity adjustment.

[0054] In this embodiment, the V-shaped conveyor belt 15 is made of acid and alkali resistant rubber material; the size of the elliptical roller 11 can be customized according to the swing amplitude.

[0055] By limiting the material selection and dimensional customization of key components, the system's environmental tolerance and process adaptability are enhanced. The V-shaped conveyor belt 15 is made of acid and alkali resistant rubber material, enabling it to resist corrosion from acidic and alkaline chemical mists or potentially splashing chemicals commonly found in etching production line environments. This material property prevents the belt from hardening, cracking, swelling, or weakening after prolonged contact with corrosive media, thus ensuring the long-term reliable operation of the transmission system in harsh chemical environments and extending the service life of vulnerable parts. The size of the elliptical roller 11 can be customized according to the required swing amplitude, providing flexibility to adapt to different production process requirements. The major and minor axis dimensions of the elliptical roller 11 directly determine the lifting stroke of the spray frame lifting linkage 12, and thus the swing amplitude of the spray nozzle assembly. By customizing elliptical rollers 11 of different sizes, the longitudinal scanning range of the spray liquid flow on the board surface can be easily adjusted, thereby meeting the process requirements of different board heights, different etching uniformity accuracy requirements, or different spraying modes, enhancing the equipment's versatility and adjustability. Example 2

[0056] In this embodiment, a more specific implementation of a vertical spray etching system is provided, which aims to demonstrate a parametric design that can meet the specific needs of fine line fabrication.

[0057] The core of the system includes two spray units arranged opposite each other, forming a spray channel through which the printed circuit board passes vertically. Each spray unit includes a spray frame fixing body 1, on which a U-shaped groove spray frame guide rail 3 is provided. The guide rail is equipped with guide rail pulleys 31 to reduce friction and is reinforced by U-shaped groove guide rail fixing buckles 4 to ensure structural stability.

[0058] The spraying execution section consists of four vertically arranged nozzle assemblies, numbered from top to bottom as: first nozzle assembly 5, second nozzle assembly 6, third nozzle assembly 7, and fourth nozzle assembly 8. Each nozzle assembly comprises multiple connected nozzles; in this embodiment, the total nozzle length of each assembly is set to 750 mm. Nozzles 9 for spraying the etching solution are mounted on the nozzles, with the following specific distribution parameters: the first nozzle assembly 5 has a relatively large number of nozzles 9, with an installation spacing of approximately 30 mm; the number of nozzles 9 in the second nozzle assembly 6 decreases sequentially, while the installation spacing increases to approximately 36 mm; the number of nozzles 9 in the third nozzle assembly 7 further decreases, with an installation spacing of approximately 47 mm; and the fourth nozzle assembly 8 has the fewest nozzles 9, with an installation spacing of approximately 53 mm. Furthermore, the nozzles 9 on each nozzle assembly are staggered in the horizontal direction to avoid overlapping jet projections.

[0059] The spray module is driven by a drive mechanism in which the two ends of the spray frame lifting link 12 are eccentrically connected to two elliptical rollers 11. The elliptical rollers 11 are fixedly mounted on the conveyor spindle 13. In this embodiment, an exemplary dimension of the elliptical rollers 11 is a height of 80 mm and a width of 40 mm. The middle part of the spray frame lifting link 12 is fixedly connected to the spray module, which consists of four spray pipe combinations: a first spray pipe combination 5, a second spray pipe combination 6, a third spray pipe combination 7, and a fourth spray pipe combination 8, via a spray pipe connecting screw 10.

[0060] Power is provided by a main transmission motor and belt 20. This motor drives the transmission rollers 14 mounted on the main transmission shaft 13 via a V-shaped transmission belt 15, thereby causing the entire main transmission shaft 13 and the elliptical rollers 11 fixed thereon to rotate synchronously. The V-shaped transmission belt 15 can be made of acid and alkali resistant rubber material, with a cross-sectional thickness of approximately 10 mm and a width of approximately 25 mm to withstand corrosive environments. The main transmission motor and belt 20 are protected by a transmission motor protective cover 21.

[0061] Drive principle: When the main shaft 13 rotates, the two elliptical rollers 11 rotate synchronously, driving the two ends of the spray frame lifting linkage 12 to make circular motion through their eccentric structure. Since the middle part of the spray frame lifting linkage 12 is rigidly connected to the spray module, and the spray module is constrained by the U-shaped groove spray frame guide rail 3, the circular motion is converted into a precise up-and-down reciprocating linear motion of the middle part of the spray frame lifting linkage 12, thereby driving the entire spray module to swing up and down synchronously along the U-shaped groove spray frame guide rail 3.

[0062] Each nozzle assembly is equipped with an independent liquid supply and control system. The first nozzle assembly 5, the second nozzle assembly 6, the third nozzle assembly 7, and the fourth nozzle assembly 8 are each connected to an independent etching solution supply pipe 19. Each etching solution supply pipe 19 is equipped with a control valve 18 and an automatic pressure regulating device 17, thereby achieving independent and precise control of the spray pressure of each nozzle assembly. Considering that the nozzle assemblies need to oscillate back and forth during operation, a flexible transparent telescopic sleeve 16 is used to connect the etching solution supply pipe 19 to each nozzle assembly to compensate for movement displacement and facilitate observation of the internal flow conditions.

[0063] This embodiment demonstrates an optimized implementation through the specific dimensional configuration and parameter design described above. The gradient distribution of the number of nozzles 9, decreasing from top to bottom while increasing in spacing, combined with the reciprocating oscillation of the spray module, aims to dynamically adjust the etchant coverage density and impact time at different heights on the vertically passing board surface. An independent pressure control system allows for fine-tuning of the gradient spray effect. This collaborative design helps achieve a more uniform etching effect in the vertical direction of the board surface, reducing vertical variations and thus supporting the fabrication of fine circuit patterns with high linewidth / spacing requirements. The corrosion-resistant materials and protective design used in the system also consider long-term operational reliability in wet chemical processes such as developing and etching. Example 3

[0064] In this embodiment, a printed circuit board production line is provided, including at least one vertical spray etching system as described above, and the conveying device of the production line is configured to drive the printed circuit board vertically through a spray channel formed by two systems arranged opposite each other.

[0065] Integrating the aforementioned vertical spray etching system into a printed circuit board (PCB) production line defines its specific application scenarios and configurations, protecting the entire production line containing this innovative system. Its value lies not only in the spray system itself but also in the overall solution for its collaborative operation with other parts of the production line (especially the vertical conveyor). The configuration, designed to drive PCBs vertically through the relatively positioned spray system, clarifies the necessary spatial layout and material flow for the system to function on the production line. This integration ensures that the vertical spray etching process can be seamlessly embedded into existing PCB manufacturing processes, enabling process upgrades for specific steps (such as developing or etching). Using this system on the production line leverages its advantages—improved etching uniformity, reduced pooling effect, and enhanced ability to fabricate fine lines—to comprehensively improve the production line's product yield, process stability, and technological advancement when processing high-precision PCBs.

[0066] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A vertical spray etching system for a printed circuit board, comprising a first spray unit and a second spray unit with identical structural components arranged opposite each other to form a spray channel, wherein both the first spray unit and the second spray unit include a spray frame fixing body (1) and U-shaped groove spray frame guide rails (3) respectively disposed on the spray frame fixing body (1), characterized in that, Also includes: The spray module is slidably mounted on the U-shaped groove spray frame guide rail (3). The spray module includes multiple spray pipe combinations arranged in the vertical direction, and the number of nozzles (9) contained in each spray pipe combination decreases one by one along the direction from top to bottom. The nozzle drive mechanism includes a drive shaft, at least one elliptical roller (11) fixed on the drive shaft, and a spray frame lifting link (12); the two ends of the spray frame lifting link (12) are respectively eccentrically connected to the corresponding elliptical roller (11), and the middle part of the spray frame lifting link (12) is connected to the spray module in a transmission manner; when the drive shaft rotates, the elliptical roller (11) drives the spray frame lifting link (12), thereby driving the spray module to swing up and down along the U-shaped groove spray frame guide rail (3).

2. The vertical spray etching system according to claim 1, characterized in that, The plurality of nozzle assemblies include a first nozzle assembly (5), a second nozzle assembly (6), a third nozzle assembly (7) and a fourth nozzle assembly (8) arranged from top to bottom, and the nozzles (9) on each nozzle assembly are staggered, with the number of nozzles (9) gradually decreasing from top to bottom.

3. The vertical spray etching system according to claim 1, characterized in that, The U-shaped groove spray frame guide rail (3) is provided with guide rail pulleys (31) for reducing sliding resistance and is reinforced by U-shaped groove guide rail fixing buckles (4). The spray module has V-shaped guide surfaces (32) on both sides that cooperate with the guide rail pulleys (31). The spray pipe drive mechanism also includes a transmission main shaft (13) driven by a main transmission motor and belt (20). The transmission main shaft (13) constitutes the drive shaft. The elliptical roller (11) is fixedly mounted on the transmission main shaft (13).

4. The vertical spray etching system according to claim 3, characterized in that, The main transmission motor and belt (20) are provided with a transmission motor protective cover (21); a transmission roller (14) is installed on the transmission spindle (13), and the main transmission motor and belt (20) drive the transmission roller (14) and the transmission spindle (13) to rotate through the V-shaped transmission belt (15).

5. The vertical spray etching system according to claim 1, characterized in that, The spray module is fixedly connected to the spray frame lifting link (12) by the spray pipe connecting screw (10).

6. The vertical spray etching system according to claim 2, characterized in that, The first nozzle assembly (5), the second nozzle assembly (6), the third nozzle assembly (7) and the fourth nozzle assembly (8) are respectively supplied with etching solution through independent etching solution supply pipes (19), and each etching solution supply pipe (19) is equipped with a control valve (18) and an automatic pressure regulating device (17).

7. The vertical spray etching system according to claim 6, characterized in that, The etching solution supply pipe (19) is connected to the nozzle assembly via a flexible transparent telescopic sleeve (16).

8. The vertical spray etching system according to claim 2, characterized in that, The nozzles in the first nozzle assembly (5), the second nozzle assembly (6), the third nozzle assembly (7) and the fourth nozzle assembly (8) have the same length, and the distance between the nozzles (9) on the nozzle increases from top to bottom.

9. The vertical spray etching system according to claim 4, characterized in that, The V-shaped conveyor belt (15) is made of acid and alkali resistant rubber material; the size of the elliptical roller (11) can be customized according to the swing amplitude.

10. A printed circuit board production line, characterized in that, The production line includes at least one vertical spray etching system as described in any one of claims 1 to 9, wherein the conveying device is configured to drive the printed circuit board vertically through a spray channel formed by two of the systems arranged opposite each other.

Images