A spray system and method for preventing pressure marks and indentations on the grinding section of a PCB board.

Abstract

This invention relates to the field of PCB cleaning technology, specifically a spray system and method for preventing pressure marks and indentations in the grinding section of a PCB board. It includes: a frame, a PCB board conveying channel, a grinding brush assembly, an upper spray pipe assembly, a lower spray pipe assembly, a conveying and holding roller assembly, a controller, and a sensor assembly. The upper and lower spray pipe assemblies are distributed along the PCB board's travel direction in the areas before grinding, the grinding brush roller area, the area connecting adjacent grinding brush rollers, the conveying and holding roller assembly area, and the area after grinding. They are equipped with board surface nozzles, grinding brush nozzles, steel roller cleaning nozzles, and rubber roller cleaning nozzles. The controller controls the opening and closing of corresponding spray positions based on the PCB board's travel status signals collected by the sensor assembly, achieving pre-wetting before grinding, cooling and powder removal in the grinding area, cleaning of the steel rollers and conveying rubber rollers before entering the board, and final cleaning after grinding, reducing pressure marks and indentations caused by copper powder or foreign matter entering the holding area along with the board surface and roller surfaces.

Description

Technical Field

[0001] This invention relates to the field of PCB board cleaning technology, specifically a spray system and method for preventing pressure marks and indentations on the grinding section of a PCB board. Background Technology

[0002] During the pretreatment of PCB boards for solder mask, copper surface roughening, or board surface grinding, it is usually necessary to remove oxides, dust, copper powder, and other foreign matter from the board surface through methods such as brushing and spray washing to ensure that the PCB board surface meets the requirements of subsequent solder mask, development, or other surface treatment processes. Existing patent literature has disclosed a variety of technical solutions related to PCB board grinding, spray cleaning, or pretreatment for solder mask.

[0003] For example, patent document CN204031600U discloses a PCB solder mask pretreatment production line, which sets up a sprayer between a grinding machine and a sandblasting machine to spray the PCB board after grinding and before sandblasting, so as to reduce the problem of copper surface oxidation points caused by copper powder residue after grinding. This solution focuses on the spray cleaning of the board surface after grinding and before sandblasting.

[0004] For example, patent document CN104619122B discloses a method for manufacturing a printed circuit board, which includes brushing the PCB surface with a nylon brush and a water washing and spraying step. The copper powder generated on the PCB surface by brushing is cleaned by water washing and spraying, and the spraying pressure parameters are recorded. This solution indicates that copper powder is generated during the brushing process and needs to be removed by water spraying.

[0005] For example, patent document CN108282966A discloses a PCB solder resist pretreatment process, which includes steps such as automatic feeding, volcanic ash grinding, roughening, micro-etching, board surface cleaning, drying, cooling, and automatic board collection. This process improves the adhesion between the PCB board's copper surface, holes, and solder resist ink by controlling the roughness and cleanliness of the copper surface. This solution focuses on board surface roughening, cleaning, and automated conveying in the PCB solder resist pretreatment process.

[0006] As can be seen from the existing technologies described above, current PCB grinding or solder mask pretreatment equipment has recognized that the grinding process generates copper powder and has adopted methods such as spraying and washing to remove residues from the PCB board surface. However, the above solutions mainly focus on the overall cleaning of the board surface after grinding, the roughening effect of the board surface, or the cleaning between processes. The spraying action is usually concentrated on the PCB board surface itself, or the board surface is only rinsed in the subsequent process after grinding.

[0007] In actual PCB grinding, surface scratches and indentations are not entirely caused by uncleaned surfaces. They are also related to the transfer of copper powder, grinding debris, and foreign matter between the PCB surface, grinding rollers, steel rollers, and conveyor rollers during the grinding process. Especially before contacting the PCB, if copper powder or foreign matter adheres to the surface of the steel rollers and conveyor rollers, this residue can easily enter the pressure contact area between the rollers and the PCB, where it is again pressed onto the PCB surface, resulting in scratches, indentations, or localized abrasions. Simply spraying the PCB surface once after grinding, or only performing a regular water wash, is insufficient to promptly remove copper powder and foreign matter before the steel rollers and conveyor rollers enter the board, as well as in the areas where adjacent grinding rollers connect. Summary of the Invention

[0008] The purpose of this invention is to provide a spray system and method for preventing pressure marks and indentations in the grinding section of a PCB board, so as to solve the technical problems mentioned in the background art.

[0009] Based on the above ideas, the present invention provides the following technical solution: A PCB board grinding section anti-dent spraying system includes: It includes a frame, PCB board conveying channel, grinding brush assembly, upper spray pipe assembly, lower spray pipe assembly, conveying and holding roller assembly, controller, and sensor assembly; The PCB board conveying channel is arranged inside the frame along the PCB board traveling direction; The grinding brush group is disposed in the grinding area of ​​the PCB board conveying channel, and the grinding brush group includes multiple grinding brush rollers arranged sequentially along the PCB board traveling direction; The conveying and holding roller group is disposed at the PCB board conveying channel, and the conveying and holding roller group includes a steel roller for holding the PCB board and a conveying rubber roller for conveying the PCB board; The upper spray pipe group and the lower spray pipe group are respectively arranged above and below the PCB board conveying channel, and are distributed along the PCB board traveling direction in the areas before the PCB board enters the grinding area, in the areas corresponding to each grinding brush roller, in the connecting areas between adjacent grinding brush rollers, in the areas corresponding to the conveying and holding roller group, and after the PCB board exits the grinding area. The upper spray pipe assembly and the lower spray pipe assembly include a board surface nozzle facing the PCB board surface, a grinding brush nozzle facing the grinding brush roller, a steel roller cleaning nozzle facing the steel roller surface, and a rubber roller cleaning nozzle facing the conveying rubber roller surface. The sensor assembly is used to collect the travel status signal of the PCB board in the PCB board conveying channel. The controller is connected to the sensor assembly, the upper spray pipe group and the lower spray pipe group respectively, and controls the opening and closing of the corresponding spray position according to the travel status signal. Before the PCB board enters the grinding area, the board surface nozzles pre-wet the upper and lower surfaces of the PCB board; as the PCB board passes through each grinding brush roller, the grinding brush nozzles spray the grinding brush rollers and the grinding area to cool the grinding brush rollers and remove the copper powder generated during grinding; before the steel roller contacts the PCB board, the steel roller cleaning nozzles rinse the surface of the steel roller; before the conveying rubber roller contacts the PCB board, the rubber roller cleaning nozzles rinse the surface of the conveying rubber roller; after the PCB board exits the grinding area, the board surface nozzles perform a final wash on the upper and lower surfaces of the PCB board.

[0010] Preferably, the upper spray pipe group includes multiple upper spray pipes arranged at intervals along the PCB board traveling direction, and the lower spray pipe group includes multiple lower spray pipes arranged at intervals along the PCB board traveling direction. The upper spray pipes and the lower spray pipes are respectively set to the PCB board pre-wetting area, the area corresponding to the grinding brush roller, the connection area between adjacent grinding brush rollers, the roller surface cleaning area, and the final washing area.

[0011] Preferably, the PCB board is provided with upper and lower corresponding board surface nozzles before entering the grinding area. The upper and lower corresponding board surface nozzles are located above and below the PCB board conveying channel, respectively, and spray towards the upper and lower surfaces of the PCB board, so as to pre-wet the PCB board surface and initially remove the board dust before the PCB board enters the grinding brush group.

[0012] Preferably, each set of grinding brush rollers is provided with grinding brush nozzles on the front and rear sides along the PCB board traveling direction. The grinding brush nozzles spray towards the corresponding grinding brush roller and grinding area to pre-cool the grinding brush roller, cool the grinding area, and carry away the copper powder generated during grinding from the corresponding grinding area.

[0013] Preferably, the steel roller cleaning nozzle is located on the board entry side before the steel roller contacts the PCB board. The steel roller cleaning nozzle sprays towards the steel roller surface, and the spraying direction of the steel roller cleaning nozzle is opposite to the rotation direction of the corresponding steel roller, so as to clean the copper powder and foreign matter on the steel roller surface before the steel roller rolls into the PCB board.

[0014] Preferably, a lower conveying rubber roller is provided after the front part of the grinding brush roller along the PCB board traveling direction. The rubber roller cleaning nozzle is located on the board entry side before the corresponding lower conveying rubber roller contacts the PCB board. The rubber roller cleaning nozzle sprays towards the roller surface of the lower conveying rubber roller, and the spraying direction of the rubber roller cleaning nozzle is opposite to the rotation direction of the corresponding lower conveying rubber roller, so as to clean the copper powder and foreign matter on the roller surface of the lower conveying rubber roller.

[0015] Preferably, a set of board surface nozzles is provided before the steel roller corresponding to the grinding brush roller at the end along the PCB board traveling direction. The spraying direction of the set of board surface nozzles is inclined in the opposite direction to the PCB board traveling direction, so as to clean the PCB board surface before the PCB board enters the steel roller corresponding to the end grinding brush roller.

[0016] Preferably, the nozzles in the upper and lower spray pipe groups have fan-shaped spray surfaces, a preset spray distance is maintained between the nozzle outlet and the PCB board surface, and the spray areas of adjacent nozzles have a preset overlap rate; the spray pipes in the upper and lower spray pipe groups adopt a detachable quick-install structure and are connected to a flow regulating valve for adjusting the spray flow rate; the spray system also includes a water supply circulation component, which includes a clean water tank, a multi-stage centrifugal pump, a filter barrel, a main water supply pipe, a return water tank, a sewage sedimentation tank, and a copper powder recovery device, wherein the clean water tank, multi-stage centrifugal pump, filter barrel, main water supply pipe, upper spray pipe group, lower spray pipe group, return water tank, sewage sedimentation tank, and copper powder recovery device are sequentially connected to the clean water tank.

[0017] A method for preventing pressure damage and indentation in the grinding section of a PCB board using a spray system for preventing pressure damage and indentation in the grinding section of a PCB board, the method comprising: S1. Before the PCB board enters the grinding area along the PCB board conveying channel, the upper and lower surfaces of the PCB board are pre-wetted by the board surface nozzles located above and below the PCB board conveying channel. S2. When the PCB board passes through the grinding brush assembly, the grinding brush nozzles set on the front and rear sides of the grinding brush roller spray the grinding brush roller and the grinding area to cool the grinding brush roller and the grinding area and remove the copper powder generated during grinding. S3. Before the steel roller contacts the PCB board, the surface of the steel roller is cleaned by a steel roller cleaning nozzle with a spray direction opposite to the rotation direction of the steel roller. S4. Before the conveyor rollers come into contact with the PCB board, the surface of the conveyor rollers is cleaned by roller cleaning nozzles that spray in the opposite direction to the rotation direction of the conveyor rollers. S5. The PCB board enters the steel roller corresponding to the grinding brush roller located at the end along the PCB board's travel direction, and the PCB board surface is cleaned by the board surface nozzles that are set in the opposite direction to the PCB board's travel direction. S6. After the PCB board exits the grinding area, the upper and lower surfaces of the PCB board are finally washed by the board surface nozzles located above and below the PCB board conveying channel.

[0018] Preferably, during the spraying process, the controller controls the opening and closing of the corresponding spraying positions in the upper and lower spray pipe groups according to the PCB board travel status signal collected by the sensor components; the sprayed water is sprayed out sequentially through the clean water tank, multi-stage centrifugal pump, filter barrel, main water supply pipe, upper spray pipe group and lower spray pipe group, and then flows back to the return water tank, and is treated by the sewage sedimentation tank and copper powder recovery device before flowing back to the clean water tank.

[0019] The technical solution of the present invention may include the following beneficial effects: This invention provides spray positions along the PCB board's travel direction, corresponding to the board surface before grinding, the grinding brush roller, the steel roller surface, the conveying rubber roller surface, the board surface before the end steel roller, and the board surface after grinding. Before entering the grinding area, the PCB board is pre-wetted on both the upper and lower surfaces, reducing the risk of dry grinding when the grinding brush roller initially contacts the board surface. As the PCB board passes the grinding brush roller, the brush nozzles spray the grinding brush roller and the grinding area, cooling the grinding brush roller and promptly removing copper powder generated during grinding. This reduces the likelihood of copper powder being crushed again as the PCB board enters the next grinding position, thereby improving the cleanliness and surface roughness consistency of the board surface after grinding.

[0020] Furthermore, the steel roller cleaning nozzle is located on the board entry side before the steel roller contacts the PCB board, and the spray direction is opposite to the rotation direction of the steel roller. This allows for the rinsing of copper powder and foreign matter adhering to the steel roller surface before the steel roller grinds into the PCB board. Similarly, the rubber roller cleaning nozzle is located on the board entry side before the conveyor rubber roller contacts the PCB board, and the spray direction is opposite to the rotation direction of the conveyor rubber roller. This reduces the amount of material adhering to the surface of the conveyor rubber roller that enters the board contact area with the roller. Thus, the spraying target is expanded from a single board surface to the steel roller and conveyor rubber roller that directly contact the PCB board. This allows for cleaning of critical contact areas before indentations and damage are formed, reducing the transfer of copper powder, shavings, and foreign matter between the board surface, brush, steel roller, and rubber roller, and their subsequent embedment into the PCB board surface. The reverse-tilted board surface spraying nozzle located before the end steel roller can also directionally remove residual copper powder before the PCB board enters the final pressing position, further reducing the risk of indentations and damage at the end of the grinding process.

[0021] The sensor assembly collects data on the PCB board's position, conveyor speed, spray pressure, and spray flow rate. Based on this data, the controller determines the start and stop times, the number of nozzles to be opened, and the flow rate adjustment value for each spray position. This ensures that pre-wetting spray, brush spray, steel roller cleaning, rubber roller cleaning, end-of-line board cleaning, and final washing are matched to the actual PCB board's position and the actual water output from the spray pipeline. Compared to fixed-time, fixed-flow spraying methods, this approach reduces issues such as premature or delayed spraying, insufficient spraying, and no-board spraying caused by variations in conveyor speed, board length, board spacing, or water output fluctuations. It ensures effective cleaning of the roller and board surfaces while reducing ineffective water spraying and maintains a relatively stable anti-dent / indentation effect of the segmented spraying structure under continuous production conditions. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural diagram of the anti-dent spraying system for the PCB board grinding section in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the forward structural arrangement of the anti-dent spraying system for the PCB board grinding section in Embodiment 1 of the present invention; Figure 3This is a schematic flowchart of the anti-dent spraying method for the PCB board grinding section in Embodiment 1 of the present invention; Figure 4 This is a flowchart illustrating the process of generating spray control commands based on the PCB board's travel state and spraying state in Embodiment 2 of the present invention. In the picture: 1. Frame; 2. PCB board conveying channel; 3. Grinding brush assembly; 4. Upper spray pipe assembly; 5. Lower spray pipe assembly; 6. Conveying and holding roller assembly. Detailed Implementation

[0023] Example 1 like Figure 1 and Figure 2 As shown, this embodiment provides a PCB board grinding section anti-pressure scratch spraying system, including a frame 1, a PCB board conveying channel 2, a grinding brush group 3, an upper spray pipe group 4, a lower spray pipe group 5, and a conveying pressure roller group 6.

[0024] The PCB board conveying channel 2 is located within the frame 1 along the PCB board's travel direction, allowing the PCB board to continuously pass through the grinding section. The grinding brush assembly 3 is positioned within the grinding area of ​​the PCB board conveying channel 2 to grind the PCB board surface. The conveying and holding roller assembly 6 is located at the PCB board conveying channel 2 to convey, support, and hold the PCB board, ensuring stable movement during the grinding process. The upper spray pipe assembly 4 is positioned above the PCB board conveying channel 2, and the lower spray pipe assembly 5 is positioned below it. The upper and lower spray pipe assemblies 4 and 5 are arranged along the PCB board's travel direction, corresponding to the areas before the PCB board enters the grinding area, the area where the grinding brush rollers are located, the connection area between adjacent grinding brush rollers, the area where the conveying and holding roller assembly 6 is located, and the final washing area after the PCB board exits the grinding area. The customer briefing clearly states that an upper spray pipe group, a lower spray pipe group, and a grinding brush roller are set along the PCB board's travel direction, and that the board surface is pre-wetted, the grinding brush is cooled, copper powder is removed, the steel roller is cleaned, the conveyor roller is cleaned, and the final wash is achieved through nozzles at different positions.

[0025] In this embodiment, the grinding brush group 3 includes four sets of grinding brush rollers arranged sequentially along the PCB board's travel direction. The upper spray pipe group 4 includes six upper spray pipes arranged sequentially along the PCB board's travel direction, and the lower spray pipe group 5 includes five lower spray pipes arranged sequentially along the PCB board's travel direction. The above quantities are specific quantities set according to the existing grinding section structure in this embodiment, used to illustrate the correspondence between the spray pipes and the grinding brush rollers, steel rollers, conveying rubber rollers, and the board surface cleaning area. In other embodiments, the number of upper and lower spray pipes can be adjusted according to the number of grinding brush rollers, the PCB board width, the equipment length, and the spray coverage requirements.

[0026] Nozzles are installed on the upper spray pipe assembly 4 and the lower spray pipe assembly 5, respectively. Depending on the object being sprayed, the nozzles include board surface nozzles, abrasive brush nozzles, steel roller cleaning nozzles, and rubber roller cleaning nozzles. Board surface nozzles are positioned towards the upper or lower surface of the PCB board for pre-wetting, surface cleaning, and final washing. Abrasive brush nozzles are positioned towards the corresponding abrasive brush roller and abrasive area for supplying water to the abrasive brush roller and abrasive area. Steel roller cleaning nozzles are positioned towards the surface of the steel roller to rinse the steel roller surface before it contacts the PCB board. Rubber roller cleaning nozzles are positioned towards the surface of the conveyor rubber roller to rinse the conveyor rubber roller surface before it contacts the PCB board.

[0027] The conveying and holding roller assembly 6 includes steel rollers and conveying rubber rollers. The steel rollers are used to hold or support the PCB board during conveying and grinding, while the conveying rubber rollers drive the PCB board forward along the PCB board conveying channel 2. Copper powder, grinding debris, or other foreign matter generated during the grinding process easily adheres to the surface of the steel rollers or conveying rubber rollers. When the steel rollers or conveying rubber rollers contact the PCB board again, the adhering substances may be carried into the contact area between the roller surface and the PCB board, causing pressure marks, indentations, or localized scratches on the PCB board surface. Therefore, in this embodiment, in addition to surface spraying, corresponding roller surface cleaning nozzles are also provided before the steel rollers and conveying rubber rollers contact the PCB board.

[0028] like Figure 3 As shown, the spraying method in this embodiment is performed according to the order in which the PCB board passes through the grinding section.

[0029] S1. Before the PCB board enters the grinding area, the upper and lower surfaces are pre-wetted and the initial dust is rinsed off simultaneously.

[0030] Before the PCB board enters the grinding area along the PCB board conveyor channel 2, the nozzles above the PCB board conveyor channel 2 spray the upper surface of the PCB board, while the nozzles below the PCB board conveyor channel 2 spray the lower surface of the PCB board. After the upper and lower surfaces are pre-wetted simultaneously, the dust and loose particles attached to the PCB board surface are initially washed away, and the board surface is in a wet state before entering the grinding brush group 3. This pre-wetting spray can reduce the risk of dry grinding when the grinding brush rollers initially contact the PCB board, and reduce the burning and indentation caused by localized drying of the board surface, dust retention, or frictional heating.

[0031] S2. When the PCB board passes through the grinding brush roller, the grinding brush and grinding area are sprayed with water to cool them and remove copper powder.

[0032] Each set of grinding brush rollers is equipped with grinding brush nozzles on both the front and rear sides along the PCB board's travel direction. As the PCB board passes over the grinding brush rollers, the grinding brush nozzles spray water towards the corresponding grinding brush roller and grinding area. The grinding brush nozzles located on the front side of the grinding brush rollers supply water to the grinding brush rollers and the area near the board surface before the PCB board enters that grinding position, while the grinding brush nozzles located on the rear side of the grinding brush rollers are used to promptly flush away the copper powder and grinding debris generated after grinding. The sprayed water continuously acts near the grinding brush rollers, cooling the grinding brush rollers and grinding area, while simultaneously carrying the newly generated copper powder away from the corresponding position, reducing the possibility of copper powder being crushed again when it enters the next grinding brush roller along with the PCB board.

[0033] S3. Before the steel roller contacts the PCB board, rinse the surface of the steel roller in the opposite direction of rotation.

[0034] Each set of abrasive brush rollers is equipped with a cleaning nozzle at its corresponding roller position. The cleaning nozzle is located on the board entry side before the roller contacts the PCB board, and faces the roller surface. The spray direction of the cleaning nozzle is opposite to the rotation direction of the corresponding roller, directing the spray water towards and rinsing off any adhering substances on the roller surface. Before entering the contact area with the PCB board, the roller surface is rinsed by the spray water, removing copper powder, abrasive shavings, and foreign matter. This prevents them from being carried into the pressure contact area between the roller and the PCB board, thus reducing pressure marks and indentations caused when the roller grinds into the PCB board.

[0035] S4. Before the conveyor rollers come into contact with the PCB board, rinse the surface of the conveyor rollers in the opposite direction of rotation.

[0036] In this embodiment, a lower conveyor roller is provided after the first set of grinding brush rollers along the PCB board traveling direction. Specifically, a roller cleaning nozzle is provided at the first lower conveyor roller after the first two sets of grinding brush rollers. The roller cleaning nozzle is located on the board entry side before the corresponding lower conveyor roller contacts the PCB board and is oriented towards the roller surface. The spray direction of the roller cleaning nozzle is opposite to the rotation direction of the corresponding lower conveyor roller. Copper powder and foreign matter easily adhere to the surface of the conveyor roller. Reverse rinsing removes these adhering substances before the conveyor roller contacts the PCB board, reducing the amount of copper powder entering the board contact area with the roller and minimizing wear on the roller surface caused by long-term copper powder adhesion.

[0037] S5. Before the PCB board enters the end steel roller, it is sprayed with water at a reverse angle to clean the residual copper powder on the board surface.

[0038] A set of board surface nozzles is positioned before the steel roller at the end of the PCB board's travel direction. These nozzles are tilted in the opposite direction to the PCB board's travel direction. Before the PCB board enters the final steel roller, these nozzles spray the PCB board surface at a reverse tilt, causing residual copper powder to be washed away by water flow opposite to the board's travel direction. In a preferred embodiment, these nozzles are tilted 15° in the opposite direction to the PCB board's travel direction. After the initial grinding, a small amount of copper powder may still be present on the PCB board. If this copper powder enters the final steel roller, it can easily form indentations during the final pressing process. By performing reverse tilt cleaning before the final steel roller, the likelihood of residual copper powder being pressed into the PCB board surface at the final steel roller can be reduced.

[0039] S6. After the PCB board exits the grinding area, perform a final cleaning on the upper and lower surfaces to remove residual copper shavings.

[0040] After the PCB board exits the grinding area, the nozzles located above and below the PCB board conveyor channel 2 spray the upper and lower surfaces of the PCB board again. This spraying is used for a final cleaning of the PCB board, removing copper powder, grinding shavings, and debris remaining on the board surface during the aforementioned grinding and roller cleaning processes. This ensures that the PCB board leaves the grinding section with a relatively clean surface, facilitating its entry into subsequent processing steps.

[0041] In this embodiment, each nozzle is preferably a fan-shaped nozzle. The nozzle spray surface is preferably an 80° fan shape, the distance from the nozzle outlet to the PCB board surface is preferably 100mm to 200mm, and the overlap rate of the spray areas of adjacent nozzles is preferably 20%. With the above settings, the spray water can form a relatively uniform coverage area in the width direction of the PCB board, reducing spray blind spots; the retention of a certain overlap area between adjacent nozzles can reduce the impact of insufficient water volume at the spray edge area on the board surface cleaning effect. The above-mentioned spray angle, spray distance, and overlap rate are preferred parameters in this embodiment, and those skilled in the art can adjust them according to the PCB board width, nozzle specifications, water supply pressure, and equipment installation space.

[0042] The spray pipes in the upper spray pipe assembly 4 and the lower spray pipe assembly 5 adopt a detachable quick-connect structure. The spray pipes are connected to the water supply pipeline through quick-connect couplings, which can adopt a snap-fit, threaded locking, or plug-in sealing connection structure. A safe distance is maintained between the spray pipes and the grinding brush assembly 3, the steel roller, and the conveying rubber roller, so that operators do not need to remove the grinding brush roller, steel roller, and conveying rubber roller when disassembling the spray pipes, cleaning the nozzles, or replacing the nozzles. The spray pipes are also equipped with flow regulating valves, which are used to adjust the spray flow rate of the corresponding spray pipes or spray areas to adapt to PCB boards of different thicknesses, widths, and materials. For PCB boards with larger widths, larger grinding amounts, or more copper powder generation, the spray flow rate at the corresponding spray position can be appropriately increased; for thinner PCB boards or those with higher surface requirements, the spray flow rate can be appropriately reduced to avoid excessive water flow impact.

[0043] This embodiment also includes a water supply circulation assembly. The water supply circulation assembly includes a clean water tank, a multi-stage centrifugal pump, a filter barrel, a main water supply pipe, a return water tank, a wastewater sedimentation tank, and a copper powder recovery device. Spray water is output from the clean water tank, pressurized by the multi-stage centrifugal pump, and then enters the filter barrel. The filtered spray water is then sent through the main water supply pipe to the upper spray pipe assembly 4 and the lower spray pipe assembly 5, and sprayed out from each nozzle. The sprayed water, carrying copper powder, grinding debris, and other particles, flows into the return water tank, then into the wastewater sedimentation tank for settling. After the copper powder is recovered by the copper powder recovery device, the treated water flows back to the clean water tank for reuse. This water circuit reduces spray water waste and facilitates centralized treatment of copper powder generated during grinding. The circulation relationship of the clean water tank, multi-stage centrifugal pump, filter barrel, main water supply pipe, each spray bar, return water tank, wastewater sedimentation tank, copper powder recovery device, and return clean water tank is described in the disclosure document.

[0044] In this embodiment, the spray system may also include a controller and a sensor assembly. The controller is connected to the sensor assembly, the upper spray pipe group 4, and the lower spray pipe group 5, respectively. The sensor assembly is used to collect the travel status signal of the PCB board within the PCB board conveying channel 2. Based on this travel status signal, the controller controls the corresponding spray positions to open or close, ensuring that the PCB board is sprayed by corresponding nozzles when it enters the pre-wetting area, the area corresponding to the grinding brush roller, the side where the steel roller enters the board, the side where the conveying rubber roller enters the board, and the final washing area. In this embodiment, the sensor assembly is described from a higher-level perspective; its specific detection components and control logic will be further explained in subsequent embodiments.

[0045] In this embodiment, multiple spray positions are set along the PCB board's travel direction in the PCB board grinding section, with the spray targets corresponding to the PCB board surface, grinding brush roller, steel roller surface, and conveyor rubber roller surface, respectively. The PCB board is pre-wetted before entering the grinding area; copper powder generated during grinding is promptly flushed away by the brush nozzles; the steel roller and conveyor rubber roller are cleaned before contacting the PCB board; the PCB board undergoes reverse tilting cleaning before entering the final steel roller; and a final wash is performed after the PCB board exits the grinding area. This spray system reduces the transfer of copper powder and foreign matter between the PCB board surface, grinding brush roller, steel roller, and conveyor rubber roller, lowering the risk of surface scratches and indentations during the grinding section.

[0046] Example 2 like Figure 4 This embodiment further defines the cooperation method between the sensor assembly and the controller. The sensor assembly is specifically configured to include a board arrival detection component, a conveying speed detection component, a spray pressure detection component, and a spray flow detection component. The board arrival detection component is used to collect the arrival status of the PCB board after it enters the PCB board conveying channel 2; the conveying speed detection component is used to collect the conveying speed of the PCB board in the PCB board conveying channel 2; the spray pressure detection component is used to collect the water supply pressure of the corresponding spray zone in the upper spray pipe group 4 and the lower spray pipe group 5; and the spray flow detection component is used to collect the actual spray flow of the corresponding spray zone.

[0047] The board arrival detection device can be installed on the board entry side of the PCB board conveying channel 2, or it can be installed before the pre-wetting area, before the area corresponding to the grinding brush roller, on the board entry side of the steel roller, on the board entry side of the conveying rubber roller, and before the final washing area, depending on the equipment space. A through-beam photoelectric detector is preferred for the board arrival detection device, but a reflective photoelectric detector or a proximity detector can also be used. The conveying speed detector is preferably installed at the conveying rubber roller, conveying roller shaft, or conveying drive motor, and can be an encoder, speed measuring wheel, or motor speed acquisition unit. The spray pressure detector is installed at the main water supply pipe or the branch pipe of the spray zone, and the spray flow detector is installed at the inlet pipe of the corresponding spray zone.

[0048] The controller can be a PLC, industrial controller, or embedded control unit. The sheet material arrival detection device is connected to the controller's digital input terminal, the conveying speed detection device is connected to the controller's high-speed counting terminal or pulse input terminal, and the spray pressure and spray flow detection devices are connected to the controller's analog input terminal or communication interface. The controller's output terminals are connected to the solenoid valves, flow regulating valves, proportional valves, or water supply pump frequency converters of each spray zone to control the opening and closing of each spray zone and the spray flow rate.

[0049] In this embodiment, the spray system is divided into multiple spray zones according to the sprayed object, including at least a pre-wetting spray zone, a brush spray zone, a steel roller cleaning zone, a rubber roller cleaning zone, a front plate cleaning zone for the end steel roller, and a final wash spray zone. Each spray zone corresponds to a plate surface nozzle, a brush nozzle, a steel roller cleaning nozzle, and a rubber roller cleaning nozzle, respectively. Let the spray zone number be i, with different i corresponding to different spray zones.

[0050] The spraying method in this embodiment includes: S1. Generate spray control commands based on the PCB board's movement and spraying status. After the PCB board enters the PCB board conveyor channel, the sensor assembly collects the PCB board's arrival status, conveying speed, and the water supply pressure and actual spray flow rate of the corresponding spray zone. Based on these detection signals, the controller determines the opening and closing times, the number of open nozzles, and the opening degree of the flow regulating valve for each spray zone, and generates corresponding spray control commands. These spray control commands are used to control the pre-wetting spray zone, brush spray zone, steel roller cleaning zone, rubber roller cleaning zone, end steel roller front plate cleaning zone, and final wash spray zone to execute their respective spraying actions.

[0051] S1 specifically includes: S1.1 Collect data on the PCB board's arrival status, conveying speed, and spraying status; After the PCB board enters the PCB board conveying channel 2, the board arrival detection device collects the time it takes for the leading edge of the PCB board to pass the reference detection position and records it as t0; the board arrival detection device collects the time it takes for the trailing edge of the PCB board to pass the same reference detection position and records it as t1. The reference detection position is preferably the board entry detection position located in front of the pre-wetting spray zone, but it can also be other detection positions with known coordinates in the equipment.

[0052] The conveying speed detection device collects the conveying speed of the PCB board within the PCB board conveying channel 2, denoted as v, with units of m / s. The controller calculates the PCB board length L based on t0, t1, and v, i.e., L is equal to the product of the PCB board conveying speed and the time difference between the leading and trailing edges of the PCB board passing the reference detection position. The PCB board width W can be input via the equipment's human-machine interface along with the production recipe, or it can be obtained by a width detection device or a multi-point board arrival detection device; in this embodiment, it is preferred that the operator inputs it in the production recipe, and the controller then retrieves it.

[0053] The spray pressure sensor collects the actual water supply pressure P of the i-th spray zone. i The unit is MPa. The spray flow rate sensor collects the actual spray flow rate Q of the i-th spray zone. iThe unit is L / s. For spray pressure and spray flow signals, the controller preferably collects data with a sampling period of 100ms to 200ms and calculates the moving average value using a time window of 1s to 3s. For the plate arrival signal, the controller preferably collects data with a scan period of 10ms to 20ms and sets a de-jitter time of 20ms to 50ms. For the conveyor speed signal, the controller preferably calculates the average speed using a time window of 100ms to 500ms.

[0054] When the board arrival signal is briefly missing for no more than 0.5 seconds, the controller calculates the current position of the PCB board based on the most recent valid arrival signal and the current conveying speed. When the board arrival signal is continuously missing for more than 0.5 seconds, the controller stops receiving new board entry control and shuts down the currently running spray zone after a safety delay. For spray pressure and spray flow signals, if a single sampling point experiences a sudden change, the controller replaces that sampling point with the median value within adjacent sampling time windows; if the pressure or flow rate of the same spray zone is continuously lower than the set range, the system enters the S7 anomaly handling phase.

[0055] S1.2. Obtain the spray window X based on the PCB board's travel status and the spray zone position; The controller uses the PCB board leading edge arrival time t0, conveying speed v, PCB board length L, PCB board width W, and the distance D between each spray zone and the reference detection position to determine the PCB board's position. i Determine the spray window X of the i-th spray zone. i .

[0056] In this embodiment, the spray window X i Including the start time t of the i-th sprinkler zone i on, off time t i ,off and the number of nozzles n that need to be opened along the width of the PCB board. i Let l i τ is the advance action length of the i-th spray zone, in meters; i p represents the response time of the i-th spray zone from valve opening to the stable arrival of spray water at the action position, in seconds. i r represents the spacing between adjacent nozzles in the i-th spray zone along the width of the PCB board, in meters. i Reserved spray coverage for the PCB board's width edge, in meters. The spray window X of the i-th spray zone. i Determine using the following formula:

[0057] Among them, X i t represents the spray window of the i-th spray zone; i,on t represents the start-up time of the i-th sprinkler zone;i,off Let n be the shut-off time of the i-th sprinkler zone; i t0 is the number of nozzles opened along the width of the PCB board in the i-th spray zone; t0 is the time it takes for the leading edge of the PCB board to pass the reference detection position; D i v is the distance from the reference detection position to the center of action of the i-th spray zone; v is the PCB board conveying speed; L is the PCB board length; l i τ is the advance action length; i R is the spray response time; W is the PCB board width; r i p represents the edge spray coverage. i Nozzle spacing; symbol This indicates rounding up to the nearest integer.

[0058] Sprinkler window X i This is used to determine that each spray zone should be activated before the PCB board reaches its corresponding position and deactivated after the trailing edge of the PCB board leaves its corresponding area of ​​action. For the pre-wetting spray zone, X i The nozzles on the board surface are pre-wetted before the PCB board enters the grinding brush group 3; for the grinding brush spraying zones, X i The abrasive brush nozzle pre-cools the abrasive brush roller before it reaches the PCB board, and continues to flush away copper powder briefly after the PCB board passes through; for the steel roller cleaning zone and the rubber roller cleaning zone, X i The corresponding roller surface is rinsed before contacting the PCB board; for the final rinse spray zone, X i This ensures that the PCB board receives complete spray coverage as it passes through the final washing area, and reduces the amount of empty spraying in areas without boards.

[0059] In this embodiment, the controller calculates the spray window Xi only when the conveying speed v is within the normal operating speed range of the equipment. When the conveying speed is lower than the minimum operating speed set by the equipment, the controller does not generate a new traveling spray window and processes it as a standby cleaning or shutdown state.

[0060] S1.3. Obtain the effluent correction coefficient Y based on the spray pressure and spray flow rate. After obtaining the spray window Xi, the controller determines the effluent correction coefficient Y based on the spray pressure and spray flow rate of the i-th spray zone. i The water discharge correction factor Yi is used to reflect the degree of matching between the actual water discharge capacity of the spray zone and the current PCB board conveying speed, board width, and cleaning intensity requirements.

[0061] Let λ i The target spray volume per unit area for the i-th spray zone is expressed in L / m². 2 W represents the PCB board width in meters (m); v represents the PCB board conveying speed in meters per second (m / s); Q i P represents the actual spray flow rate of the i-th spray zone, in L / s.i The actual water supply pressure of the i-th sprinkler zone is expressed in MPa. The calibrated water supply pressure for the i-th spray zone is given in MPa. The effluent correction factor Yi for the i-th spray zone is determined by the following formula:

[0062] Where, λ i W v Q represents the target spray flow rate required for the i-th spray zone under the current PCB width and conveyor speed; i This indicates the actual spray flow rate of the spray zone; This is used to reflect the deviation of the actual water supply pressure from the calibrated water supply pressure. When the actual water supply pressure decreases, the flushing speed and spray stability of the spray water will decrease, so the pressure term is used to correct the water output condition.

[0063] When Y i When Y approaches 1, it indicates that the actual effluent condition of the spray zone basically matches the target spraying requirements; when Y... i When Y is greater than 1, it indicates that the current actual water output or water supply pressure is insufficient, requiring an increase in the opening of the corresponding flow regulating valve or an extension of the spraying action; when Y i When the value is less than 1, it indicates that the current actual water output is relatively high. The opening of the corresponding flow regulating valve can be reduced to decrease ineffective water use.

[0064] When P i Or Q i If the value is zero, or if the output of the spray pressure sensor or spray flow sensor is disconnected, short-circuited, or exceeds the range, the controller will not calculate Y according to the above formula. i Instead, it determines the corresponding spray zone as having abnormal water output and proceeds to S7 for processing.

[0065] λ i The settings are determined through equipment calibration. Different values ​​can be set for the pre-wetting spray zone, brush spray zone, steel roller cleaning zone, rubber roller cleaning zone, end steel roller front plate surface cleaning zone, and final wash spray zone. i The λ values ​​for the brush spray zone, steel roller cleaning zone, and rubber roller cleaning zone. i Typically higher than the pre-wetting spray zone, because this type of spray zone needs to remove fresh copper powder and clean the roller surface of any adhering substances. λ i The amount of grinding can be determined based on the PCB board material, grinding amount, grinding brush roller speed, board surface cleanliness requirements, and trial production results.

[0066] S1.4. Obtain the spray control command Z based on the spray window X and the outlet water correction coefficient Y. The controller obtains the spray window X based on S1.2. iThe effluent correction factor Y obtained from S1.3 i Generate the spray control command Z for the i-th spray zone. i Sprinkler control command Z i This includes the opening time, closing time, number of open nozzles, and flow control valve opening of the i-th spray zone.

[0067] set up The reference valve opening for the i-th spray zone is expressed in % (%). Let be the minimum allowable valve opening for the i-th spray zone; Let be the maximum permissible valve opening for the i-th spray zone. The spray control command Zi is determined by the following formula:

[0068] Among them, Z i This is the spray control command for the i-th spray zone; t i,on t i,off and n i From sprinkler window X i ;Y i This is the effluent correction factor; The reference valve opening; This is the minimum permissible valve opening. This represents the maximum permissible valve opening.

[0069] When Y i When the value is between 0.90 and 1.10, the controller executes spraying according to the reference valve opening. When Y... i When Y is greater than 1.10, the controller increases the opening of the corresponding flow regulating valve to compensate for insufficient actual water output. i When the value is less than 0.90, the controller reduces the opening of the corresponding flow regulating valve, but not below the minimum allowable valve opening, to ensure that the spray water can still cover the corresponding action area.

[0070] S1.4 output Z i This serves as the basis for the subsequent execution of S2 to S6. The brush nozzles in S2, the steel roller cleaning nozzles in S3, the rubber roller cleaning nozzles in S4, the nozzles on the front surface of the end steel roller in S5, and the final cleaning nozzles on the surface of the plate in S6 are all executed according to the Z-axis of their respective spray zones. i Perform start / stop and flow regulation.

[0071] S2. Perform brush spraying according to the corresponding spray control command; When the PCB board passes through the grinding brush group 3, the controller sprays the brushes according to the Z-zone corresponding to the grinding brush spraying zone. i Open the abrasive nozzles located on the front and rear sides of the abrasive roller. The abrasive nozzles at the corresponding t... i,on Starts at any time, at the corresponding t i,offAlways turn off, and follow Z. i The valve opening in the process regulates the spray flow rate. When the conveying speed increases, the spray window obtained in S1.2 is moved forward accordingly; when the actual spray pressure or spray flow rate decreases, S1.3 and S1.4 increase the opening of the corresponding flow regulating valve. As a result, the grinding brush roller is pre-cooled before it reaches the PCB board, and the copper powder generated during the grinding process is promptly flushed away at the corresponding position.

[0072] S3. Perform steel roller surface cleaning according to the corresponding spray control command; Before the steel rollers contact the PCB board, the controller follows the Z-axis corresponding to the steel roller cleaning zone. i Turn on the steel roller cleaning nozzles. The nozzles are positioned facing the steel roller surface, and the spray direction is opposite to the roller's rotation direction. The controller determines the activation time of this spray zone based on the PCB board conveying speed and the position of the steel roller on the board entry side, ensuring the steel roller surface is rinsed with spray water before contacting the PCB board. If the spray pressure or flow rate is insufficient, the controller increases the opening of the corresponding flow regulating valve, ensuring the steel roller surface is cleaned before entering the pressure contact area.

[0073] S4. Perform conveyor roller surface cleaning according to the corresponding spray control command; Before the conveyor rollers contact the PCB board, the controller adjusts the Z-axis according to the roller cleaning zone. i Turn on the rubber roller cleaning nozzles. The rubber roller cleaning nozzles are positioned facing the surface of the conveyor rubber roller, and the spraying direction is opposite to the rotation direction of the conveyor rubber roller. For the lower conveyor rubber roller, which is prone to copper powder adhesion after the front grinding brush roller, the controller determines the opening and closing time of the rubber roller cleaning nozzles based on the PCB board's arrival status and conveying speed, so that the surface of the conveyor rubber roller is rinsed before contacting the PCB board.

[0074] S5. Clean the front plate of the end steel roller according to the corresponding spray control command; The PCB board enters the grinding brush roller located at the end of the PCB board's travel direction, corresponding to the steel roller. The controller then cleans the board surface according to the Z-zone corresponding to the cleaning zone in front of the end steel roller. i Activate the reverse-tilted nozzles on the PCB surface. These nozzles are tilted in the opposite direction to the PCB's travel direction to flush away residual copper powder as the PCB moves forward. The controller determines the spray window for each cleaning zone based on the distance from the reference detection position to the front cleaning zone of the end roller, the PCB conveying speed, and the PCB length. This prevents dry spraying before the PCB arrives and also avoids starting cleaning only after the PCB has entered the end roller.

[0075] S6. Perform the final wash after mill exit according to the corresponding spray control command; After the PCB board exits the grinding area, the controller proceeds according to the Z-zone corresponding to the final wash spray zone. iThe nozzles located above and below the PCB conveyor channel 2 are activated to perform a final wash on the upper and lower surfaces of the PCB. The opening and closing times of the final wash spray zone are determined based on the leading and trailing edges of the PCB, ensuring complete spray coverage as the PCB passes through the final wash area. For continuous production with small board spacing, if the next PCB is about to enter the final wash area, the controller can keep the final wash spray zone running continuously to avoid frequent valve opening and closing. For production with large board spacing, the controller closes the final wash spray zone after the trailing edge of the current PCB leaves the final wash area to reduce dry spraying in areas without boards.

[0076] S7. Exception handling and degraded operation are performed during the execution of S1 to S6; During execution from S1 to S6, the controller continuously assesses the pressure and flow status of each spray zone. If the Y value of a certain spray zone... i If the flow rate consistently exceeds the set upper limit, and the corresponding flow regulating valve has reached its maximum allowable opening, the controller determines that there is nozzle blockage, increased filter resistance, or insufficient water supply in that spray zone. At this time, the controller issues an alarm signal and may reduce the PCB board conveying speed or prevent new PCB boards from entering PCB board conveying channel 2. For PCB boards that have already entered the grinding section, the controller maintains necessary board surface spraying and roller surface cleaning, allowing the PCB board to complete the current grinding process before stopping the machine for inspection.

[0077] If the board arrival detection device malfunctions briefly, but the conveyor speed detection device functions normally, the controller calculates the PCB board position based on the most recent valid arrival signal and the current conveyor speed, and maintains the current PCB board to complete the corresponding spraying process. If the board arrival detection device continues to malfunction, the controller will no longer accept new board entry signals and will switch the spraying system to a fixed low-flow cleaning state or a shutdown pending inspection state. If the conveyor speed detection device malfunctions, the controller will no longer use speed to calculate the spray window, but will switch to a preset fixed window spraying mode and prompt the system to check the conveyor speed detection device.

[0078] During equipment installation and commissioning, parameters for each spray zone should be calibrated. The parameters that need to be calibrated include: the distance D from the reference detection position to the center of action of each spray zone. i The response time τ of each spray zone from valve opening to the stable arrival of spray water at the target position. i ; advance action length l i Nozzle spacing p i Edge spray coverage r i ; Calibrated water supply pressure Reference valve opening Minimum permissible valve opening Maximum permissible valve opening Target spraying rate per unit area λ i .

[0079] D i It can be determined based on the dimensions in the equipment drawings and on-site measurements. i The value λ can be determined by the time difference between the valve opening signal and the spray pressure reaching a stable value. i This can be determined through trial production with different PCB board specifications. During calibration, PCB boards of different widths, lengths, and conveyor speeds are selected for trial operation. The amount of residual copper powder on the board surface, the deposits on the steel roller surface, the deposits on the conveyor roller surface, the water consumption, and the indentation defects are recorded after spraying. The lower, stable spray volume that meets the requirements for board surface cleanliness and roller surface cleanliness can be used as the λ for the corresponding spray zone. i Basis for value selection.

[0080] The calibrated parameters are stored in the controller and can be used to generate production formulas according to PCB board specifications. During production, the operator selects the PCB board specifications on the equipment's human-machine interface, the controller calls the corresponding formula, and executes steps S1 to S7 after the PCB board enters the PCB board conveying channel. This control method does not require offline model training; it mainly relies on equipment size calibration, online sensor detection, and real-time calculations by the controller.

Claims

1. A spray system for preventing pressure marks and indentations in the grinding section of a PCB board, characterized in that, include: It includes a frame (1), a PCB board conveying channel (2), a grinding brush group (3), an upper spray pipe group (4), a lower spray pipe group (5), a conveying pressure roller group (6), a controller, and a sensor assembly; The PCB board conveying channel (2) is located within the frame (1) along the PCB board traveling direction; The grinding brush group (3) is disposed in the grinding area of ​​the PCB board conveying channel (2), and the grinding brush group (3) includes multiple grinding brush rollers arranged sequentially along the PCB board traveling direction; The conveying and holding roller group (6) is located at the PCB board conveying channel (2). The conveying and holding roller group (6) includes a steel roller for holding the PCB board and a conveying rubber roller for conveying the PCB board. The upper spray pipe group (4) and the lower spray pipe group (5) are respectively located above and below the PCB board conveying channel (2), and are distributed along the PCB board traveling direction in the areas before the PCB board enters the grinding area, in the corresponding areas of each grinding brush roller, in the connecting areas between adjacent grinding brush rollers, in the corresponding areas of the conveying pressure roller group (6), and after the PCB board exits the grinding area. The upper spray pipe assembly (4) and the lower spray pipe assembly (5) include a board surface nozzle facing the PCB board surface, a grinding brush nozzle facing the grinding brush roller, a steel roller cleaning nozzle facing the steel roller surface, and a rubber roller cleaning nozzle facing the conveying rubber roller surface. The sensor assembly is used to collect the travel status signal of the PCB board in the PCB board conveying channel (2). The controller is connected to the sensor assembly, the upper spray pipe group (4) and the lower spray pipe group (5) respectively, and controls the opening and closing of the corresponding spray position according to the travel status signal. Before the PCB board enters the grinding area, the board surface nozzles pre-wet the upper and lower surfaces of the PCB board; when the PCB board passes through each grinding brush roller, the grinding brush nozzles spray the grinding brush rollers and the grinding area to cool the grinding brush rollers and remove the copper powder generated during grinding. Before the steel roller comes into contact with the PCB board, the steel roller cleaning nozzle rinses the surface of the steel roller. Before the conveying rubber roller comes into contact with the PCB board, the rubber roller cleaning nozzle rinses the surface of the conveying rubber roller; after the PCB board exits the grinding area, the board surface nozzle performs a final wash on the upper and lower surfaces of the PCB board.

2. The PCB board grinding section anti-dent spraying system according to claim 1, characterized in that, The upper spray pipe group (4) includes multiple upper spray pipes arranged at intervals along the PCB board traveling direction, and the lower spray pipe group (5) includes multiple lower spray pipes arranged at intervals along the PCB board traveling direction. The upper spray pipes and the lower spray pipes are respectively set to the PCB board pre-wetting area, the area corresponding to the grinding brush roller, the connection area between adjacent grinding brush rollers, the roller surface cleaning area, and the final cleaning area.

3. The PCB board grinding section anti-dent spraying system according to claim 2, characterized in that, Before the PCB board enters the grinding area, there are corresponding upper and lower board surface nozzles. The corresponding upper and lower board surface nozzles are located above and below the PCB board conveying channel (2) respectively, and spray towards the upper and lower board surfaces of the PCB board respectively, so as to pre-wet the PCB board surface and initially remove the board surface dust before the PCB board enters the grinding brush group (3).

4. The PCB board grinding section anti-dent spraying system according to claim 3, characterized in that, Each set of grinding brush rollers is provided with grinding brush nozzles on the front and rear sides along the PCB board traveling direction. The grinding brush nozzles spray towards the corresponding grinding brush roller and grinding area to pre-cool the grinding brush roller, cool the grinding area, and carry away the copper powder generated during grinding away from the corresponding grinding area.

5. The PCB board grinding section anti-dent spraying system according to claim 4, characterized in that, The steel roller cleaning nozzle is located on the board entry side before the steel roller contacts the PCB board. The steel roller cleaning nozzle sprays towards the steel roller surface, and the spraying direction of the steel roller cleaning nozzle is opposite to the rotation direction of the corresponding steel roller, so as to clean the copper powder and foreign matter on the steel roller surface before the steel roller rolls into the PCB board.

6. The PCB board grinding section anti-dent spraying system according to claim 5, characterized in that, A lower conveying rubber roller is provided after the grinding brush roller located at the front section along the PCB board traveling direction. The rubber roller cleaning nozzle is located on the board entry side before the corresponding lower conveying rubber roller contacts the PCB board. The rubber roller cleaning nozzle sprays towards the roller surface of the lower conveying rubber roller, and the spraying direction of the rubber roller cleaning nozzle is opposite to the rotation direction of the corresponding lower conveying rubber roller, so as to clean the copper powder and foreign matter on the roller surface of the lower conveying rubber roller.

7. The PCB board grinding section anti-dent spraying system according to claim 6, characterized in that, A set of board surface nozzles is provided before the steel roller corresponding to the grinding brush roller at the end along the PCB board's travel direction. The spraying direction of the set of board surface nozzles is inclined in the opposite direction to the PCB board's travel direction, so as to clean the PCB board surface before the PCB board enters the steel roller corresponding to the end grinding brush roller.

8. A PCB board grinding section anti-dent spraying system according to claim 6, characterized in that, The nozzles in the upper spray pipe group (4) and the lower spray pipe group (5) have a fan-shaped spray surface, and the nozzle outlet maintains a preset spray distance with the PCB board surface. The spray areas of adjacent nozzles have a preset overlap rate. The spray pipes in the upper spray pipe group (4) and the lower spray pipe group (5) adopt a detachable quick-install structure and are connected to a flow regulating valve for adjusting the spray flow rate. The spray system also includes a water supply circulation component, which includes a clean water tank, a multi-stage centrifugal pump, a filter barrel, a main water supply pipe, a return water tank, a sewage sedimentation tank, and a copper powder recovery device. The clean water tank, the multi-stage centrifugal pump, the filter barrel, the main water supply pipe, the upper spray pipe group (4), the lower spray pipe group (5), the return water tank, the sewage sedimentation tank, the copper powder recovery device, and the clean water tank are connected in sequence.

9. A method for preventing pressure marks and indentations in the grinding section of a PCB board using spraying, characterized in that, The PCB board grinding section anti-dent spraying system according to any one of claims 1 to 8, the method comprising: S1. Before the PCB board enters the grinding area along the PCB board conveying channel (2), the upper and lower surfaces of the PCB board are pre-wetted by the board surface nozzles located above and below the PCB board conveying channel (2). S2. When the PCB board passes through the grinding brush group (3), the grinding brush nozzles set on the front and rear sides of the grinding brush roller spray the grinding brush roller and the grinding area to cool the grinding brush roller and the grinding area and remove the copper powder generated during grinding. S3. Before the steel roller contacts the PCB board, the surface of the steel roller is cleaned by a steel roller cleaning nozzle with a spray direction opposite to the rotation direction of the steel roller. S4. Before the conveyor rollers come into contact with the PCB board, the surface of the conveyor rollers is cleaned by roller cleaning nozzles that spray in the opposite direction to the rotation direction of the conveyor rollers. S5. The PCB board enters the steel roller corresponding to the grinding brush roller located at the end along the PCB board's travel direction, and the PCB board surface is cleaned by the board surface nozzles that are set in the opposite direction to the PCB board's travel direction. S6. After the PCB board exits the grinding area, the upper and lower surfaces of the PCB board are finally washed by the board surface nozzles located above and below the PCB board conveying channel (2).

10. A method for preventing pressure marks and indentations in the grinding section of a PCB board according to claim 9, characterized in that: During the spraying process, the controller controls the opening and closing of the corresponding spraying positions in the upper spray pipe group (4) and the lower spray pipe group (5) according to the PCB board travel status signal collected by the sensor components. The sprayed water is sprayed out sequentially through the clean water tank, multi-stage centrifugal pump, filter barrel, main water supply pipe, upper spray pipe group (4) and lower spray pipe group (5), and then flows back to the return water tank. After being treated by the sewage sedimentation tank and copper powder recovery device, it flows back to the clean water tank.

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