A PCB coating device integrating feeding and coating

Abstract

The application relates to a surface coating liquid device, in particular to a PCB coating device integrating feeding and coating. The device mainly comprises a base plate, a screw guide rail group and a feeding and coating integrated module integrating a feeding mechanism and a coating mechanism. The innovation core lies in that: the feeding mechanism adopts a multi-head discharging design, ensuring uniform and stable feeding; the coating mechanism realizes constant-pressure soft contact between a coating roller and a PCB board through an elastic floating assembly, effectively preventing the PCB board from being damaged; smooth anti-permeation sections are arranged at the two ends of the coating roller, which can significantly inhibit the permeation and accumulation of slurry at the edges of the PCB board, improving the coating uniformity in the board. The above-mentioned structure integration synchronously solves the three problems of uneven discharging, edge halo permeation and poor process compatibility in the prior art, and realizes the optimized balance among coating quality, production efficiency and equipment adaptability.

Description

TECHNICAL FIELD

[0001] The present application relates to a surface coating liquid device, in particular to a PCB coating device integrating feeding and coating. BACKGROUND

[0002] In the process of PCB manufacturing, coating is a key step before the exposure of circuit pattern, which provides uniform photosensitive coating for the subsequent formation of circuit. Among them, the roll coating method is widely used due to its high coating efficiency and suitability for large area construction. However, the existing roll coating method coating equipment has the following technical defects, which seriously restricts its application effect and range. First, in terms of coating process quality, the existing technology has the following problems:

[0003] 1. Uneven discharge: the traditional single-hole feeding system cannot guarantee the stable and uniform delivery of slurry to the coating roller, resulting in fluctuations in the thickness of the slurry coated on the PCB board, affecting the consistency of the finished product.

[0004] 2. Edge effect / halo phenomenon is obvious: this is a stubborn defect of roll coating method. The slurry accumulates too thick at the edge of the PCB board due to fluid dynamics and surface tension, forming uneven edge profile, which seriously affects the coating quality of fine line PCB, and even leads to product unqualified.

[0005] Secondly, in terms of process compatibility and safety, most of the existing equipment adopts the coating method of hard contact between the roller and the PCB board. This rigid contact method requires high pressure control, and any slight negligence may easily damage the precision or thin substrate, such as causing thin board deformation, flexure or surface scratch, which greatly limits its application on high-end, thin and light PCB products. SUMMARY

[0006] The purpose of the present application is to overcome the defects of the existing PCB roll coating equipment, and to provide a PCB coating device integrating feeding and coating, which can improve the coating quality.

[0007] In order to achieve the above-mentioned purpose of the application, the following technical scheme is adopted: a PCB coating device integrating feeding and coating, the key points of which are as follows: it includes a substrate, a set of parallel arranged screw guide rail groups, and a feeding and coating integrated module. The substrate is used to position and fix the PCB board. The screw guide rail groups are erected on both sides of the substrate, one side of which includes a screw rod, a first guide rail and a second guide rail, and the first guide rail and the second guide rail are respectively located on both sides of the screw rod. A third guide rail is located on the other side of the substrate and is driven to rotate by a motor. The feeding and coating integrated module is integrally provided with a feeding mechanism and a coating mechanism. The feeding and coating integrated module is located above the screw guide rail group and is driven to reciprocate along the screw guide rail group by the screw guide rail group.

[0008] The feeding and coating integrated module comprises a fixed frame, a feeding mechanism and a coating mechanism, first and second sliding blocks are fixed at the lower ends of the two sides of the fixed frame, the first sliding block is provided with threads matched with the screw rod, so that the fixed frame moves under the driving of the screw rod, the screw rod drives the fixed frame to move forward and backward, the first and second guide rails are used for supporting the two sides of the first sliding block, so that the transmission between the screw rod and the first sliding block is stable, and the third guide rail is used for supporting the second sliding block, so that the fixed frame moves back and forth as a whole stably, the collecting box of the feeding mechanism is fixed below the fixed frame, the collecting box comprises a feeding port and a plurality of discharge pipes, the upper cover plate of the fixed frame is provided with a through hole through which the feeding port can pass, and the coating mechanism comprises a coating roller and a roller support, the coating roller shaft is connected with the roller support, and the plurality of discharge pipes are uniformly arranged above the coating roller.

[0009] The key improvement of the application is that the collecting box with a plurality of discharge pipes is arranged.

[0010] Further design: the feeding and discharging control of the collecting box is a gas pressure linkage control mechanism, the instant opening and closing of the discharge pipes are controlled by controlling the opening and closing of the feeding port and utilizing the gas pressure change in the box, and dripping is prevented; the discharging is a liquid level balance uniform distribution mechanism, the lower edges of the discharge pipes are preset at the same reference height, and the discharge pipes are discharged synchronously only when the slurry liquid surface in the box is higher than the reference height, so that the discharge amounts of the discharge pipes are forced to be equal.

[0011] The collecting box utilizes two fluid control principles in cooperation: one is the gas pressure linkage control mechanism, the instant opening and closing of the discharge pipes are controlled by controlling the opening and closing of the feeding port and utilizing the gas pressure change in the box, and dripping is prevented; the other is the liquid level balance uniform distribution mechanism, the lower edges of the discharge pipes are preset at the same reference height, and the discharge pipes are discharged synchronously only when the slurry liquid surface in the box is higher than the reference height, so that the discharge amounts of the discharge pipes are forced to be equal. Based on the above mechanism, the plurality of discharge pipes can stably and uniformly supply slurry to the surface of the coating roller, which provides a basic guarantee for solving the uneven coating, and thus the coating quality is improved as a whole.

[0012] The coating mechanism is connected with the fixed frame through an elastic floating assembly, so that the coating roller of the coating mechanism and the PCB on the substrate form a soft contact coating mode.

[0013] This is another innovative point of the application, the coating mechanism is suspended on the fixed frame through an elastic body, so that the coating mechanism and the PCB on the substrate form a soft contact coating mode, and damage of the precise or thin substrate caused by rigid contact between the two is prevented, and the application of the device in high-end and light and thin PCB products is expanded.

[0014] The elastic floating assembly comprises an upper pull spring and a lower pressing spring, which are connected between the fixed frame and the coating roller support, and each end of the coating roller support is provided with one upper pull spring and one lower pressing spring, which are used for fixing the coating roller support and providing a pressing force for the coating roller during the working of the coating roller, and the coating roller is fixed between the coating roller supports through bearings.

[0015] The upper pull spring provides a pulling force for moving the coating roller away from the PCB board, and the lower pressing spring provides a pressing force for moving the coating roller close to the PCB board; when the coating roller is in a free state, the lowest lower plane of the coating roller is lower than the upper surface of the PCB board, and when the coating roller contacts the upper surface of the PCB board, the pressing force of the lower pressing spring is greater than the pulling force of the upper pull spring, so that the coating roller realizes soft contact with the PCB board with controllable pressure.

[0016] The elastic floating assembly of the present application is composed of a set of tension springs (two) and a set of compression springs (two), the two tension springs are respectively located at the two ends of the coating mechanism to provide an upward pulling force, and the two compression springs are also located at the two ends of the coating mechanism and have a pre-pressing, that is, the compression springs have a pre-stress in the initial state. Experimental verification shows that the working process and deformation of the elastic floating assembly are as follows: in the initial state of the coating mechanism not working, the lower pressing spring has a pre-set pre-compression deformation preferably controlled in the range of 8.2 mm to 10.3 mm, and the upper pull spring has a pre-set initial tensile deformation preferably controlled in the range of 10 mm to 15 mm, at this time, the coating roller is located about 2 mm below the surface to be coated of the PCB board. When the coating mechanism works, the roller contacts the PCB board and is lifted by a displacement (about 2 mm), and the system reaches a working balance state. At this time, the total compression deformation of the lower pressing spring is increased to preferably controlled in the range of about 10.2 mm to 12.3 mm, and the tensile deformation of the upper pull spring is correspondingly reduced to preferably controlled in the range of about 8 mm to 13 mm. Through the accurate change of the above deformation, the assembly converts the vertical displacement of the roller into stable pressure control, so as to realize constant pressure soft contact.

[0017] The middle surface of the coating roller is provided with knurling, and the edges of the two ends are provided with anti-permeation sections with smooth circumferential surfaces, which are used for reducing the adhesion of the paste at the ends of the roller, so as to inhibit the permeation and accumulation of the coating material at the edges of the PCB board.

[0018] The existing coating roller has an integral surface with equal diameter, and all are embossed, and the edge effect / halo phenomenon is obvious. The anti-permeation sections with equal diameter to the rolling sections are arranged at the two ends of the present application, so that the paste accumulated at the two ends during the rolling process is located in the anti-permeation sections, and the smooth anti-permeation sections can make the accumulated paste quickly flow into the waste pool, so as to improve the edge effect / halo phenomenon.

[0019] The substrate includes at least four positioning pins arranged on the substrate for precisely positioning the PCB board, and pressing blocks distributed at both ends of the PCB board, which act on the non-coated area of the edge of the PCB board after positioning, so that the PCB board is flatly attached to the substrate. This design ensures the flatness of the coated surface, while avoiding the obstruction or contamination of the pressing blocks to the coated area.

[0020] The coating roller includes a coating roller shaft and a silica gel layer covering the coating roller shaft. The outer surface of the middle part of the silica gel layer is provided with a plurality of circumferentially arranged tooth-shaped protrusions, and the two end parts are smooth permeation prevention sections.

[0021] The core of the coating roller is a coating roller shaft, and the outer part of the coating roller shaft is covered with a silica gel layer. The overall diameter of the coating roller is about 26.8 mm, and the total length of the silica gel layer is 118 mm. Each of the two ends of the silica gel layer is provided with a smooth permeation prevention section with a length of about 5 mm (the diameter is consistent with the diameter of the rolling section), which can significantly reduce the adhesion of the slurry at the end of the roller, thereby effectively inhibiting the accumulation of the slurry at the edge of the PCB board and eliminating the edge halo phenomenon. The middle part is a gear-like structure, and the covered length (i.e. the effective coating length) is about 108 mm. The diameter of the coating roller shaft inside is about 8 mm.

[0022] Further design: the discharge pipe is a circular pipe connected with the material collecting box through threads, and the diameter is between 1.6-5.14 mm, and the center distance between adjacent two holes is 15-20 mm. The ratio of the axial length of the feeding shaft to the diameter of the discharge pipe is 2.9-12.5. In this design, there are six discharge pipes evenly distributed on the 108 mm long rolling section, the diameter of the discharge pipe is 1.6 mm, and the center distance between adjacent two holes is about 15 mm, i.e. the ratio of the axial length of the feeding shaft to the diameter of the discharge pipe is 2.9. In the same length of 108 mm coating roller, the diameter of the discharge pipe of the prior art is 6 mm, and the ratio of the axial length of the feeding shaft to the diameter of the discharge pipe is 18. As known, the larger the ratio of the axial length of the feeding shaft to the diameter of the discharge pipe, the longer the distance that the slurry needs to spread and flow on the surface of the roller, which is easy to cause uneven coating, flow marks or dry skin due to poor flowability, surface tension and other factors. The multi-head discharge design of the present application divides the above huge coverage task into multiple parallel discharge pipes to complete cooperatively, so that each discharge pipe is only responsible for a local area which is easy to spread uniformly, thereby ensuring the consistency of the coating from the root.

[0023] The tooth-shaped protrusions form liquid storage grooves between them. The surface of the silica gel layer is processed with a circumferentially uniform arrangement of sawtooth or gear-shaped structures, thereby forming continuous grooves on the surface of the roller. The core advantage of this design is that the grooves can act as micro-pulp storage units during the coating process, providing continuous and stable pulp supply to the coating area, effectively avoiding the problem of uneven coating surface thickness caused by insufficient instantaneous supply, thereby significantly improving the uniformity of in-panel coating.

[0024] The beneficial effects of the present application are:

[0025] Significant improvement in production efficiency and stability: based on the multi-head discharge mechanism, continuous and stable feeding is realized, ensuring efficient and consistent quality in the coating process from the source.

[0026] Significant improvement in in-panel coating uniformity: the present application effectively suppresses the accumulation of pulp at the edges through the special smooth structure at both ends of the coating roller, achieving extremely high panel coating uniformity.

[0027] Significant improvement in process compatibility: the soft contact mechanism adopted stabilizes the contact pressure within a certain range, allowing the device to safely handle thin or flexible PCB boards, effectively avoiding the risk of substrate damage. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a schematic diagram of the three-dimensional structure of the present application.

[0029] Figure 2 is Figure 1 a cross-sectional view of the feeding mechanism shown in FIG. 1, showing its internal structure and working principle.

[0030] Figure 3 is Figure 1 a connection structure diagram showing the connection of the coating mechanism and the feeding mechanism through the elastic floating assembly, as well as the edge structure of the coating roller.

[0031] Figure 4 is a cross-sectional view of the coating roller.

[0032] Wherein: 1: substrate, 11: positioning pin, 12: pressing block;

[0033] 2: screw guide rail set, 21: screw rod, 22: first guide rail, 23: second guide rail, 24: third guide rail;

[0034] 3 loading and coating integrated module, 31: loading mechanism, 311: feeding port, 312: discharge pipe, 3121 limit boss, 313 material collecting box, 32: coating mechanism, 321: coating roller; 321a: coating roller shaft, 321b: silica gel layer, 321b-1: toothed protrusion, 322: impermeable section; 323: roller support, 33: first sliding block, 34: second sliding block, 35: fixing frame, 41: upper pull spring, 42: lower pressing spring, 5: motor, 6: PCB board. DETAILED DESCRIPTION

[0035] The best mode for carrying out the present application will be explained in further detail below with reference to the accompanying drawings. It should be noted that the following description is intended to explain the present application and is not intended to limit the scope of protection.

[0036] Reference Figures 1-4 The present application provides a PCB coating device integrating loading and coating.

[0037] It comprises a base plate 1, a set of parallel arranged screw rod guide rails 2, a loading and coating integrated module 3, and a control system.

[0038] The base plate 1 is used for positioning and fixing the PCB board, and it comprises at least four positioning pins 11 arranged on the base plate 1 for accurately positioning the PCB board, and pressing blocks 12 distributed at both ends of the PCB board. The four positioning pins 11 form a clearance fit with the positioning holes on the PCB board 6, achieving a positioning accuracy of ±0.05mm. After positioning, the non-coating area on the edge of the PCB board is acted on, so that it is flatly attached to the base plate 1. The positioning pins cooperate with the positioning holes on the PCB board to achieve fast and accurate positioning of the PCB board. This design ensures sufficient flatness of the coating surface, while avoiding the obstruction or contamination of the pressing blocks to the coating area.

[0039] The screw rod guide rail set 2 is erected on both sides of the base plate 1, one side of which comprises a screw rod 21, a first guide rail 22, and a second guide rail 23. The first guide rail 22 and the second guide rail 23 are respectively located on both sides of the screw rod 21, and the screw rod in the middle is driven to rotate by a motor. The control system controls the forward and reverse rotation of the motor, so as to realize the forward and reverse rotation of the screw rod. The third guide rail 24 is located on the other side of the base plate 1.

[0040] The loading and coating integrated module 3 is integrally arranged with a fixing frame 35, a loading mechanism 31, and a coating mechanism 32. The loading and coating integrated module 3 is located above the screw rod guide rail set 2 and is driven by the screw rod guide rail set 2 to move back and forth along the screw rod guide rail set 2.

[0041] The first slider 33 and the second slider 34 are respectively fixed at the lower ends of the two sides of the fixed frame, the first slider 33 has a thread matched with the screw rod 21, so that the fixed frame is moved under the driving of the screw rod, the forward and reverse rotation of the screw rod drives the fixed frame to move forward and backward, the first guide rail 22 and the second guide rail 23 are used to support the two sides of the first slider 33, so that the transmission between the screw rod and the first slider 33 is stable, and the third guide rail 24 is used to support the second slider 34, so that the whole fixed frame moves stably and reciprocally. The material collecting box 313 of the feeding mechanism 31 is fixed below the fixed frame, the material collecting box 313 comprises a feeding port 311 and a plurality of discharge pipes 312, the upper cover plate of the fixed frame is provided with a through hole through which the feeding port can pass, and the feeding port 311 is connected with an external peristaltic pump through a hose; the coating mechanism 32 comprises a coating roller 321 and a roller support 323, the coating roller shaft is connected with the roller support, and the plurality of discharge pipes 312 are uniformly arranged above the coating roller.

[0042] The material collecting box 313 uses two fluid control principles in cooperation: one is a gas pressure linkage control mechanism, the instant opening and closing of the discharge pipe is controlled by controlling the on-off of the feeding port 311, the liquid level balance distribution mechanism is used to control the discharge pipe, the discharge pipe is connected with the material collecting box through a thread, the upper end surface of each discharge pipe is higher than the bottom plane of the material collecting box, and is located at the same reference height (such as 2mm higher than the bottom surface of the material collecting box), the height is determined by the limiting boss 3121 of the discharge pipe, and the discharge pipe is discharged only when the liquid surface of the slurry in the box is higher than the reference, so that the discharge amount of each discharge pipe is equal. Based on the above mechanism, the plurality of discharge pipes can stably and uniformly supply the slurry to the surface of the coating roller 321, which provides a basic guarantee for solving the uneven coating, and thus the coating quality is improved as a whole.

[0043] The coating roller 321 comprises a coating roller shaft 321a and a silica gel layer 321b wrapped outside the coating roller shaft, the middle surface is provided with knurling as a rolling section, and the two ends are smooth and impermeable sections 322. The overall diameter of the coating roller is about 26.8mm, the total length is 118mm, the diameter of the coating roller shaft is about 8mm, the length of the rolling section (i.e. the effective coating length) is about 108mm, and the lengths of the two end impermeable sections 322 are 5mm respectively. The diameter of the impermeable section is not greater than the knurling bottom diameter of the rolling section, which can significantly reduce the adhesion of the slurry at the end of the roller, thereby effectively inhibiting the accumulation of the slurry at the edge of the PCB board and eliminating the edge seepage phenomenon. The impermeable section can also be designed as a tapered shape with a small outer diameter and a large inner diameter, which can better flow the coating liquid into the waste pool. The knurling of the middle part of the rolling section can be a straight strip or a spiral strip, and the cross section is a gear-like structure. The shape of the knurling is as follows: Figure 4The outer surface of the middle part of the silica gel layer 321b is provided with a plurality of circumferentially arranged tooth-shaped protrusions 321b-1, and the tooth-shaped protrusions 321b-1 form regular liquid storage grooves 321b-2 between adjacent protrusions, and the surface of the roller forms a continuous groove.

[0044] As shown in the drawings, the profile is in the form of a gear with a predetermined number of teeth (for example, 72 teeth). Figure 4 The key role of this gear-shaped structure is that the grooves 321b-2 can carry and store a certain amount of slurry during the coating process, and when the roller is rolled, the stored slurry can be smoothly and continuously released to the coating area, playing the role of "secondary feeding" and "dynamic compensation", completely eliminating coating defects caused by instantaneous fluctuations in feeding, and ensuring extremely high coating uniformity. It is particularly important that the silica gel layer at both ends of the roller is processed into a permeation-preventing section 322, and the length of the permeation-preventing section 322 along the axial direction of the roller is preferably 5 mm. The smooth area with this specific width can ensure that the migration of the slurry to the end of the roller is effectively isolated during the coating process, while not losing too much effective coating area, thereby achieving an optimal balance between suppressing edge bleeding and ensuring coating efficiency.

[0045] The discharge pipe 312 is a circular pipe connected to the material collecting box by threads, and there are six of them, evenly distributed on the 108 mm long rolling section, with a diameter of 1.6-5.14 mm, and the center distance between adjacent two holes is 15-20 mm. The ratio of the axial length of the feeding to the diameter of the discharge pipe is 2.9-12.5. The present application selects a diameter of 1.6 mm, and the center distance between adjacent two holes is about 15 mm, i.e. the ratio of the axial length of the feeding to the diameter of the discharge pipe is 2.9. The diameter of the discharge pipe in the prior art is 6 mm, and for a coating roller with a length of 108 mm, the ratio of the axial length of the feeding to the diameter of the discharge pipe is 18. As is known, the greater the ratio of the axial length of the feeding to the diameter of the discharge pipe, the longer the distance the slurry needs to spread and flow on the surface of the roller, which is prone to cause uneven coating, flow marks or dry skin due to differences in flowability, surface tension and other factors. The multi-head discharge design of the present application divides the above-mentioned huge coverage task into multiple parallel discharge pipes to complete cooperatively, so that each discharge pipe only needs to be responsible for a local area that is easy to spread evenly, thereby ensuring the consistency of the coating from the root.

[0046] The coating mechanism 32 is connected to the fixed frame by an elastic floating assembly, so that the coating roller 321 of the coating mechanism 32 and the PCB board on the substrate 1 form a soft contact coating mode.

[0047] The elastic floating assembly comprises an upper pulling spring 41 and a lower pressing spring 42, which are connected between the fixed frame and the coating roller support, and each of the two ends of the coating roller support is provided with one upper pulling spring 41 and one lower pressing spring 42, so as to fix the coating roller support 323 and provide a pressing force for the coating roller 321 during the working of the coating roller 321, and the two ends of the coating roller 321 are fixed between the coating roller supports through bearings.

[0048] The upper pulling spring 41 provides a pulling force for moving the coating roller 321 away from the PCB board, and the lower pressing spring 42 provides a pressing force for moving the coating roller 321 close to the PCB board; when the coating roller 321 is in a free state, the lowest lower plane of the coating roller 321 is lower than the upper surface of the PCB board, and when the coating roller 321 is in contact with the upper surface of the PCB board, the pressing force of the lower pressing spring 42 is greater than the pulling force of the upper pulling spring 41, so that the coating roller 321 realizes soft contact with the PCB board with a controllable pressing force.

[0049] The elastic floating assembly comprises an upper pulling spring 41 and a lower pressing spring 42, which are connected between the fixed frame and the coating roller support, and each of the two ends of the coating roller support is provided with one upper pulling spring 41 and one lower pressing spring 42, so as to fix the coating roller support 323 and provide a pressing force for the coating roller 321 during the working of the coating roller 321, and the two ends of the coating roller 321 are fixed between the coating roller supports through bearings.

[0050] The working process and deformation quantization of the elastic floating assembly in the example are as follows: in the initial state of the coating mechanism not working, the lower pressing spring has a preset pre-compression deformation amount, which is preferably controlled in the range of 8.2 mm to 10.3 mm, and the upper pulling spring has a preset initial stretching deformation amount, which is preferably controlled in the range of 10 mm to 15 mm, at this time, the lower surface of the coating roller is located about 2 mm below the surface to be coated of the PCB board. When the coating mechanism works, the roller contacts the PCB board and is lifted by a displacement (about 2 mm), and the system reaches a working balance state. At this time, the total compression deformation amount of the lower pressing spring is increased to about 10.2 mm to 12.3 mm, and the stretching deformation amount of the upper pulling spring is correspondingly reduced to about 8 mm to 13 mm. Through the accurate change of the deformation amount, the assembly converts the vertical displacement of the roller into stable pressure control, so as to realize constant pressure soft contact.

[0051] In the embodiment, the gravity of the coating mechanism 32 itself is a constant contribution, which is measured as 262.8 g (about 6.454 N). Through mechanical design, the pulling force provided by the upper pulling spring 41 is always less than the sum of the pressing force provided by the lower pressing spring 42 and the gravity of the coating mechanism 32 itself, so that the coating roller 321 obtains a stable net downward pressure.

[0052] The experiment proves that, to achieve the best effect, the pressure provided by the downward spring 42 is preferably controlled in the range of 2.6 N to 6.4 N; the pulling force provided by the upward spring 41 is preferably controlled in the range of 1.5 N to 5.9 N. In this configuration, in combination with the gravity 262.8 g (about 6.454 N) of the coating mechanism itself, the net downward pressure obtained by the coating roller 321 can be stabilized in the preferred interval of 7.0 N to 9.0 N.

[0053] The precise control of the net downward pressure is the key to achieve high-quality coating: if the pressure is too small, it is not enough to overcome the pulling force of the upward spring, which may cause a gap between the coating roller 321 and the surface of the PCB board 6, and cannot complete effective paste transfer; if the pressure is too large, it will make the contact pressure between the coating roller 321 and the substrate too high, not only there is a risk of damaging the thin substrate, but also it will cause the coating film to be too thin, which cannot meet the requirements of the subsequent exposure process. Through the optimization of the above parameters, the present application successfully realizes the "soft contact" between the coating roller and the PCB board, and obtains a coating with uniform thickness and meeting the process requirements on the premise of ensuring the safety of the substrate.

[0054] This is another innovative point of the present application. The coating mechanism is suspended on the fixed frame by the elastic body, so that it forms a soft contact coating mode between the coating mechanism and the PCB board on the substrate 1, preventing the rigid contact between them from damaging the precision or thin substrate, and expanding the application of the device in high-end and thin PCB products.

[0055] The working process of the device of the present application is as follows: first, the PCB board 6 is positioned on the positioning pin 11 of the substrate 1 and is flattened and fixed by using two pressing blocks 12. Then, the motor 5 is started under the control of the control system, driving the feeding and coating integrated module 3 to move forward along the screw guide rail group 2, while the feeding mechanism 31 starts feeding, and the paste is uniformly sent to the surface of the coating roller 321 and the liquid storage groove 321b-2. The coating roller 321 completes the soft contact coating on the surface of the PCB board 6 under the action of the elastic floating assembly with constant pressure. After the coating roller completes the one-way stroke, the control system is turned off.

[0056] In summary, through the above specific embodiments, the present application successfully integrates high-uniformity feeding technology and high-performance coating technology in a compact device, significantly improves production efficiency and stability, greatly improves in-coating uniformity, and significantly improves process compatibility, successfully achieving an optimized balance among high-coating quality, high-production efficiency, and high-device adaptability. Any modification and equivalent replacement made by those skilled in the art within the scope of the principles and spirit of the present application shall be included in the protection scope of the present application.

Claims

1. A PCB coating device integrating feeding and coating, characterized in that: It includes a substrate (1), a set of parallel lead screw guide rails (2), a feeding and coating integrated module (3), and a control system. The substrate (1) is used to position and fix the PCB board. The lead screw guide rails (2) are mounted on both sides of the substrate (1). One side includes a lead screw (21), a first guide rail (22), and a second guide rail (23). The first guide rail (22) and the second guide rail (23) are located on both sides of the lead screw (21), and the third guide rail (24) is located on the other side of the substrate (1) and is driven by a motor to rotate the lead screw. The feeding and coating integrated module (3) is equipped with a feeding mechanism (31) and a coating mechanism (32). The feeding and coating integrated module (3) is located above the lead screw guide rails (2) and is controlled by the lead screw guide rails (2). 2) Driven, reciprocating along the lead screw guide rail assembly (2); The feeding and coating integrated module (3) includes a fixed frame, a feeding mechanism (31) and a coating mechanism (32). The lower ends of both sides of the fixed frame are fixed with a first slider (33) and a second slider (34). The first slider (33) has a thread that cooperates with the lead screw, so that the fixed frame moves under the drive of the lead screw. The forward and reverse rotation of the lead screw drives the fixed frame to move back and forth. The first guide rail (22) and the second guide rail (23) are used to support the two sides of the first slider (33) so that the transmission between the lead screw and the first slider (33) is smooth. The third guide rail (24) is used to support the second slider (34) so ​​that the fixed frame moves back and forth smoothly as a whole. The material collection box of the feeding mechanism (31) is fixed below the fixed frame, collecting The material box includes an inlet (311) and multiple outlet pipes (312). The upper cover of the fixed frame has a through hole that allows the inlet to pass through. The coating mechanism (32) includes a coating roller (321) and a roller support. The coating roller shaft is connected to the roller support. Multiple outlet pipes (312) are evenly arranged above the coating roller. The coating mechanism (32) is connected to the fixed frame through an elastic floating component, so that the coating roller (321) of the coating mechanism (32) and the PCB board on the substrate (1) form a soft contact coating method. The elastic floating component includes an upper tension spring (41) and a lower pressure spring (42). It is connected between the fixed frame and the coating roller support. There is an upper tension spring at each end of the coating roller support. (41) and a downward spring (42) are used to fix the coating roller support and provide downward pressure to the coating roller (321) when it is working. The coating roller (321) is fixed between the coating roller supports by bearings. The upward spring (41) provides a pulling force to move the coating roller (321) away from the PCB board, and the downward spring (42) provides a pressure to move the coating roller (321) closer to the PCB board. When the coating roller (321) is in a free state, the position of its lowest lower plane is lower than the upper surface of the PCB board. When the coating roller (321) contacts the upper surface of the PCB board, the downward pressure of the downward spring (42) is greater than the pulling force of the upward spring (41), so that the coating roller (321) can achieve soft contact with the PCB board with controllable pressure.

2. The coating apparatus according to claim 1, characterized in that: The feeding and discharging control of the collection box is a pneumatic linkage control mechanism. By controlling the opening and closing of the feed inlet (311), the instantaneous opening and closing of the discharge pipe is controlled by the change of air pressure in the box to prevent leakage. The discharge is a liquid level balance distribution mechanism. By presetting the lower edge of each discharge pipe to the same reference height, the discharge is only synchronized when the liquid level of the slurry in the box overflows this reference, thereby forcibly achieving equal discharge from each discharge pipe.

3. The coating apparatus according to claim 1, characterized in that: The coating roller (321) has a knurled surface in the middle and smooth anti-penetration sections (322) on both ends to reduce the adhesion of the slurry at the ends of the roller, thereby suppressing the penetration and accumulation of coating material at the edges of the PCB board.

4. The coating apparatus according to claim 1, characterized in that: The substrate (1) includes at least four positioning pins (11) disposed on the substrate (1) for precise positioning of the PCB board, and pressure blocks (12) distributed at both ends of the PCB board, which act on the uncoated area of ​​the edge of the PCB board after positioning, so that it is flatly attached to the substrate (1).

5. The coating apparatus according to claim 3, characterized in that: The coating roller (321) includes a coating roller shaft (321a) and a silicone layer (321b) covering the coating roller shaft. The outer surface of the middle part of the silicone layer (321b) is provided with a plurality of circumferentially arranged tooth-like protrusions (321b-1), and the two ends are smooth anti-permeability sections (322).

6. The coating apparatus according to claim 1, characterized in that: The discharge pipe (312) is a round hole with a diameter between 1.6 and 5.14 mm, and the center distance between two adjacent holes is 15-20 mm.

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