Circuit board solder mask hole plugging method and device

Abstract

The invention relates to a circuit board solder mask hole plugging method, which comprises the following steps: S1, manufacturing a hole plugging bottom plate and a hole plugging screen, and processing the corresponding hole plugging bottom plate and hole plugging screen according to the size and position of a to-be-plugged hole in a circuit board; s2, coating ink for the first time, placing a circuit board between the plug hole bottom plate and the plug hole screen printing plate, and coating the ink into the to-be-plugged hole from the plug hole screen printing plate; s3, ink pressing is conducted, specifically, the ink is further extruded into the to-be-plugged hole, and the ink sinks to the lower portion in the to-be-plugged hole; s4, the ink is coated for the second time, specifically, the ink is coated to the upper portion of the interior of the to-be-plugged hole from the hole plugging screen so as to completely fill the to-be-plugged hole; and S5, returning the printing ink, and scraping redundant printing ink. According to the invention, only the same surface of the circuit board needs to be plugged, and the to-be-plugged hole can be plugged at one time through one-time screen printing without residual bubbles, so that the production process is shortened, and the hidden danger of quality failure caused by poor hole plugging quality is effectively avoided.

Description

Technical Field

[0001] The present invention relates to the field of circuit board processing, and in particular to a method and device for plugging holes in a circuit board using solder mask ink. Background Art

[0002] Circuit board solder mask ink plugging refers to the use of solder mask ink to fill the holes on the circuit board during the circuit board manufacturing process to achieve the purpose of insulation, moisture resistance, and oxidation resistance. At present, the method of circuit board plugging is generally to use silk screen plugging, and the solder mask ink is plugged into the hole by silk screen printing on both sides. However, this method is not suitable for circuit boards with high aspect ratio (diameter-to-depth) and plugging requirements. Since the holes to be plugged in this type of circuit board have a large aspect ratio, there will often be residual air in the holes after plugging and form bubbles, which affects the quality of the circuit board and easily causes the cheongsam to expand at high temperature during reflow soldering during the subsequent SMT mounting process, causing the solder mask ink in the hole to explode and fail. Summary of the invention

[0003] In view of this, the present invention provides a method and device for plugging holes with solder mask ink on a circuit board, which can effectively avoid the generation of bubbles during the process of plugging holes with solder mask ink.

[0004] The purpose of the present invention is achieved through the following technical solutions: A method for plugging holes in a circuit board with solder mask ink comprises the following steps: S1: manufacturing a plugging hole base plate and a plugging hole screen, processing the corresponding plugging hole base plate and plugging hole screen according to the size and position of the hole to be plugged on the circuit board; S2: Applying ink for the first time, placing the circuit board between the plugging bottom plate and the plugging screen, and applying the ink from the plugging screen to the holes to be plugged; S3: Pressing ink to further squeeze the ink into the hole to be plugged, so that the ink sinks to the lower part of the hole to be plugged; S4: applying ink for the second time, applying the ink from the plugging screen to the upper part of the hole to be plugged, so as to completely fill the hole to be plugged; S5: Ink returns to the oil and scrapes off excess ink.

[0005] In the above technical solution, the size and position of the holes to be plugged on the circuit board can be accurately matched by the customized plugging bottom plate and plugging screen, ensuring that the ink can be accurately filled into each hole. When plugging holes with ink, the first application of ink is carried out, the purpose of which is to fill part of the ink into the holes to be plugged first; then the ink is pressed immediately, the purpose of which is to squeeze the ink that has been filled into the holes to be plugged, so as to further replenish the ink into the holes to be plugged, and allow the ink to sink to the bottom of the holes to be plugged or even part of the ink to emerge from the other side; then the second application of ink is carried out immediately, the purpose of which is to apply the ink to the holes to be plugged, and this time the ink is applied to the upper part of the holes to be plugged, replenishing the space of the ink that was squeezed to the lower part of the holes to be plugged during the ink pressing, thereby achieving complete filling of the holes to be plugged; finally, the ink is returned to scrape off the excess ink, which plays the role of returning the oil in the opposite direction.

[0006] Therefore, the plugging method of the present invention only needs to plug the same side of the circuit board. The first ink coating, ink pressing and the second ink coating can be connected in sequence to achieve continuous operation. Compared with the traditional plugging method of double-sided silk screen printing, the present invention only needs one silk screen printing to fill the hole to be plugged at one time without residual bubbles, which not only shortens the production process, but also effectively avoids the hidden danger of quality failure caused by poor plugging quality.

[0007] Optionally, in a possible implementation, the plugging screen is made of an aluminum sheet, the aluminum sheet is provided with screen holes corresponding to the holes to be plugged, and the aperture of the screen holes is the same as or 1-3 mil smaller than the aperture of the holes to be plugged.

[0008] In the above technical solution, since the aperture of the screen hole is 1-3 mil larger or smaller than the aperture of the hole to be plugged, this small size adjustment capability ensures that the ink can be accurately aligned and filled into each hole to be plugged, greatly improving the accuracy and consistency of production. In addition, the use of aluminum sheet as the screen material not only has high strength and good mechanical stability, can effectively resist the pressure and wear during the printing process, extend the service life of the screen, but also is easy to clean and maintain, reducing long-term operating costs.

[0009] Optionally, in a possible implementation, a bottom plate hole corresponding to the hole to be plugged is provided on the plugging bottom plate, and the hole diameter of the bottom plate hole is 4-6 mil larger than the hole diameter of the hole to be plugged.

[0010] In the above technical solution, the design of the bottom plate holes and their aperture size provides sufficient space for ink filling, ensuring that the ink can flow smoothly into and fully fill the holes to be plugged, facilitating air conduction, reducing the formation of bubbles and voids, and improving filling quality and reliability.

[0011] Optionally, in a possible implementation, in step S2, before the first application of ink, the circuit board is subjected to solder mask pre-treatment: a micro-etching solution is used in combination with volcanic ash to roughen the surface of the circuit board so that the surface of the circuit board forms a plowed shape.

[0012] In the above technical solution, the roughening treatment can increase the surface area of ​​the circuit board, provide more physical attachment points for the ink, and thus significantly enhance the adhesion between the ink and the circuit board, reducing the risk of ink falling off in subsequent processes. It can also absorb the ink more effectively, ensuring that the ink is evenly distributed on the board surface, avoiding ink accumulation or loss.

[0013] Optionally, in a possible implementation, the ink pressing method is as follows: an elastic ultrasonic vibration rubber pressure wheel is used to press the plugging screen, and at the same time, a suction method is used to suction the holes to be plugged on one side of the plugging bottom plate to squeeze the ink into the holes to be plugged.

[0014] In the above technical solution, the dual action mechanism of the ultrasonic vibration rubber pressure wheel combined with the suction device can more effectively squeeze and suck the ink into the hole to be plugged, greatly improving the filling efficiency and uniformity of the ink and shortening the production cycle. It can also more effectively eliminate bubbles, reduce the occurrence of plugging defects, and improve the qualified rate of products.

[0015] Optionally, in a possible implementation, the first application of ink and the second application of ink are applied by different scrapers.

[0016] In the above technical solution, two scrapers are used in combination to realize the first and second ink coating, which is convenient for the two coating operations to be carried out at the same time, that is, the lamination and the second ink coating operation can be carried out immediately after the first ink coating, realizing seamless connection, which greatly improves the ink plugging efficiency of the circuit board. In addition, the use of different scrapers also makes it convenient to select scrapers with different characteristics according to different process requirements.

[0017] A plugging device using the above-mentioned circuit board solder mask ink plugging method includes a machine platform and a solder mask plugging module that can move relative to the machine platform. The machine platform is stacked with a plugging base plate, a circuit board to be plugged, and a plugging screen in sequence. The solder mask plugging module can be attached to the surface of the plugging screen and slide.

[0018] In the above technical solution, the plugging device realizes the automation and integration of the plugging process through the combination of the machine and the solder-proof plugging module. The machine can stably support the components of each layer, while the solder-proof plugging module can accurately slide on the surface of the plugging screen to complete the uniform coating of ink and plugging operations, greatly reducing manual intervention and improving production efficiency and consistency. In addition, the first ink coating, ink pressing and the second ink coating can all be integrated on the solder-proof plugging module, which not only saves space, but also enables the solder-proof plugging module to complete the ink plugging of the circuit board with only one silk screen.

[0019] Optionally, in a possible implementation, the anti-welding plugging module includes a mounting frame, a driving module for driving the mounting frame to move, and a front scraper, an ultrasonic vibration rubber pressure wheel, a rear scraper and an oil return scraper arranged on the mounting frame and sequentially arranged along the moving direction of the mounting frame, and the ultrasonic vibration rubber pressure wheel is elastically connected to the mounting frame.

[0020] In the above technical solution, the anti-welding plugging module integrates multiple functional components such as the front scraper, ultrasonic vibration rubber pressure wheel, rear scraper and oil return scraper. These components are arranged in sequence along the moving direction on the mounting frame to form an efficient and compact working unit. It also allows the first ink coating, ink pressing, second ink coating and ink return to be connected in sequence, thereby greatly improving the efficiency of ink plugging.

[0021] Optionally, in a possible implementation, a plurality of air suction holes are provided on the machine platform, and the plurality of air suction holes are located below the plug hole bottom plate.

[0022] In the above technical solution, during the plugging process, the ink may generate bubbles due to various reasons. If these bubbles remain in the hole, it will seriously affect the quality of the plugging and the conductivity of the circuit. By setting multiple suction holes on the machine, and these suction holes are located below the plugging bottom plate, a negative pressure area can be formed to effectively attract and discharge the bubbles in the ink, thereby ensuring the density and bubble-free state of the ink in the hole. At the same time, it can also help the ink to be filled into the plugged hole faster to a certain extent.

[0023] Optionally, in a possible implementation, an annular limiting frame is provided on the machine platform, and the annular limiting frame is arranged around the outer circumference of the plug hole bottom plate.

[0024] In the above technical solution, the design of the annular limit frame provides a precise positioning and fixing structure for the plugging bottom plate. During the plugging operation, the plugging bottom plate needs to remain stable and motionless to ensure that the ink can be accurately filled into each hole. The annular limit frame can effectively limit the movement of the plugging bottom plate by surrounding the outer circumference of the plugging bottom plate, thereby improving the stability and accuracy of the operation. In addition, during the ink coating and plugging process, the ink may overflow from the plugging area due to uneven coating or uneven pressure. The presence of the annular limit frame can act as a barrier to prevent the overflowing ink from flowing to other parts of the machine or contaminating other components. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 The present invention is a flow chart of a method for filling holes in a circuit board with ink according to an embodiment of the present invention.

[0027] Figure 2 Schematic diagram of the change of ink during the hole filling process of a circuit board according to an embodiment.

[0028] Figure 3 The figure is a schematic structural diagram of a circuit board ink hole filling device according to an embodiment.

[0029] Figure numerals: 1-machine; 11-air suction hole; 2-anti-solder plugging module; 21-mounting frame; 22-front scraper; 23-ultrasonic vibration rubber pressure wheel; 231-elastic part; 24-rear scraper; 25-oil return scraper; 3-plugging bottom plate; 4-circuit board; 5-plugging screen; 6-annular limit frame. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0032] Please refer to Figure 1 and Figure 2 This embodiment provides a method for plugging holes in a circuit board with solder mask ink, comprising the following steps: S1: Production of via plugging base plate and via plugging screen. The corresponding via plugging base plate and via plugging screen are processed according to the size and position of the holes to be plugged on the circuit board. Through customized via plugging base plate and via plugging screen, the size and position of the holes to be plugged on the circuit board can be accurately matched to ensure that the ink can be accurately filled into each hole.

[0033] S2: Apply ink for the first time. The circuit board is placed between the plugging base plate and the plugging screen. The ink is applied from the plugging screen to the holes to be plugged. When plugging holes with ink, apply ink for the first time. The purpose is to fill part of the ink into the holes to be plugged first. At this time, the ink is located in the upper part of the holes to be plugged.

[0034] S3: Pressing ink to further squeeze the ink into the hole to be plugged, so that the ink sinks to the lower part of the hole to be plugged; the purpose of pressing ink is to squeeze the ink that has been filled into the hole to be plugged in step S2, so as to further replenish and squeeze the ink into the hole to be plugged, and allow the ink to sink to the lower part of the hole to be plugged and even part of the ink to emerge from the other side.

[0035] S4: Apply ink for the second time, apply ink from the plugging screen to the upper part of the hole to be plugged to completely fill the hole to be plugged; after the ink pressing is completed, the second ink application operation is carried out, the purpose of which is to apply ink to the hole to be plugged again. This time, the ink is applied to the upper part of the hole to be plugged, which supplements the space of the ink squeezed to the lower part of the hole to be plugged during ink pressing, thereby achieving complete filling of the hole to be plugged.

[0036] S5: Ink return, scrape off excess ink. Finally, the ink return is performed, and excess ink is scraped off, which plays the role of reverse return.

[0037] The plugging method of this embodiment only needs to plug the same side of the circuit board. The first ink coating, ink pressing and the second ink coating can be connected in sequence to achieve continuous operation. Compared with the traditional plugging method of double-sided silk screen printing, this embodiment only needs one silk screen printing to fill the hole to be plugged at one time without residual bubbles, which not only shortens the production process, but also effectively avoids the hidden danger of quality failure caused by poor plugging quality.

[0038] In this embodiment, the plugging screen is made of an aluminum sheet, on which screen holes corresponding to the holes to be plugged are arranged, and the diameter of the screen holes is equal to or smaller than the diameter of the holes to be plugged by 1-3 mil. The screen holes are drilled by a drill.

[0039] Since the aperture of the screen hole is 1-3 mil larger or smaller than the aperture of the plugged hole, this small size adjustment capability ensures that the ink can be accurately aligned and filled into each plugged hole, greatly improving the accuracy and consistency of production. In addition, the use of aluminum sheet as the screen material not only has high strength and good mechanical stability, but also can effectively resist the pressure and wear during the printing process, extend the service life of the screen, and is easy to clean and maintain, reducing long-term operating costs.

[0040] In this embodiment, a bottom plate hole corresponding to the hole to be plugged is provided on the plugging bottom plate, and the aperture of the bottom plate hole is 4-6 mil larger than the aperture of the hole to be plugged. The bottom plate hole is drilled by a drill, and the design of the bottom plate hole and its aperture size provides sufficient space for the filling of ink, ensuring that the ink can smoothly flow into and fully fill the hole to be plugged, facilitating air conduction, reducing the formation of bubbles and gaps, and improving the filling quality and reliability. In addition, the plugging bottom plate can also be used as a positioning plate for positioning the placement of the circuit board. In this way, setting the aperture of the bottom plate hole larger than the hole to be plugged can also improve the fault tolerance of the circuit board positioning to a certain extent. At this time, it is only necessary to ensure that the bottom plate hole is connected to the hole to be plugged.

[0041] It should be noted that there are multiple holes to be plugged on the circuit board with different hole diameters, and the screen holes on the plugging screen and the bottom plate holes on the plugging bottom plate correspond to all the holes to be plugged on the circuit board. When applying ink, the coating operation is performed in sequence from left to right along the surface of the plugging screen by a scraper.

[0042] In step S2, before the first application of ink, the circuit board is first subjected to solder mask pretreatment: micro-etching solution is used in combination with volcanic ash to roughen the surface of the circuit board so that the surface of the circuit board forms a plowing shape. The micro-etching solution uses NPS micro-etching solution.

[0043] Roughening can increase the surface area of ​​the circuit board, increase the contact area between the circuit board surface and the ink, and provide more physical attachment points for the ink, thereby significantly enhancing the adhesion between the ink and the circuit board and reducing the risk of ink falling off in subsequent processes. It can also absorb ink more effectively, ensuring that the ink is evenly distributed on the board surface, avoiding ink accumulation or loss.

[0044] It should be noted that the ink pressing method of this embodiment is as follows: an elastic ultrasonic vibration rubber pressing wheel is used to press the plugging screen, and at the same time, air is sucked from one side of the plugging bottom plate to the hole to be plugged, so as to squeeze the ink into the hole to be plugged. Specifically, the circuit board adopts the method of pressing up and sucking down to transfer the ink into the hole to be plugged.

[0045] The dual action mechanism of the ultrasonic vibration rubber pressure wheel combined with the suction device can more effectively squeeze and suck the ink into the hole to be plugged, greatly improving the filling efficiency and uniformity of the ink and shortening the production cycle. It can also more effectively eliminate bubbles, reduce the occurrence of plugging defects, and improve the product qualification rate. The ultrasonic vibration rubber pressure wheel is elastic. Under the action of elastic force, part of the pressure wheel can be squeezed onto the plugging screen. And because the pressure wheel is a rubber structure, it is easy to deform, that is, it deforms and is partially squeezed into the hole to be plugged. At the same time, under the longitudinal wave vibration of the ultrasonic generator and the adsorption effect of the suction hole, the ink is further sunk to the lower part of the hole to be plugged, and even part of the ink emerges on the other side.

[0046] It should be noted that the first ink coating and the second ink coating are applied by different rubber scrapers. The combination of two scrapers is used to achieve the first and second ink coating, which is convenient for the two coating operations to be carried out at the same time, that is, the lamination and the second ink coating can be carried out immediately after the first ink coating, achieving seamless connection, greatly improving the ink plugging efficiency of the circuit board. In addition, the use of different scrapers also makes it easy to select scrapers with different characteristics according to different process requirements.

[0047] After the circuit board of this embodiment is plugged, a uniform amount of solder mask ink is printed on both sides of the board through a screen with a certain mesh size, and the ink is initially cured by baking at a temperature of 75 degrees for 30 minutes. Furthermore, the board surface ink is exposed by an automatic exposure machine according to the design graphic requirements, and then sodium carbonate spray development is used to remove part of the ink, exposing the copper surface area that has not been exposed and needs to be subsequently soldered for the plug-in, thereby completing the solder mask operation of the circuit board.

[0048] Please refer to Figure 3 The present embodiment also provides a plugging device using the above-mentioned circuit board 4 solder mask ink plugging method, including a machine 1 and a solder mask plugging module 2 that can move relative to the machine 1, and the machine 1 is stacked with a plugging base plate 3, a circuit board 4 to be plugged, and a plugging screen 5 in sequence, and the solder mask plugging module 2 can be attached to the surface of the plugging screen 5 and slide.

[0049] The plugging device realizes the automation and integration of the plugging process by combining the machine 1 with the solder-proof plugging module 2. The machine 1 can stably support the components of each layer, while the solder-proof plugging module 2 can accurately slide on the surface of the plugging screen 5 to complete the uniform coating of ink and plugging operations, greatly reducing manual intervention and improving production efficiency and consistency. In addition, the first ink coating, ink pressing and second ink coating can be integrated on the solder-proof plugging module 2, which not only saves space, but also enables the solder-proof plugging module 2 to complete the ink plugging of the circuit board 4 with only one silk screen.

[0050] The solder-proof plugging hole module 2 of this embodiment includes a mounting frame 21, a driving module (not shown in the figure) for driving the mounting frame 21 to move, and a front scraper 22, an ultrasonic vibration rubber pressure wheel 23, a rear scraper 24 and an oil return scraper 25 arranged on the mounting frame 21 and arranged in sequence along the moving direction of the mounting frame 21, and the ultrasonic vibration rubber pressure wheel 23 is elastically connected to the mounting frame 21. Specifically, the front scraper 22, the ultrasonic vibration rubber pressure wheel 23, the rear scraper 24 and the oil return scraper 25 are arranged in parallel and at intervals. The ultrasonic vibration rubber pressure wheel 23 can be rotatably arranged, and the elastic member 231 is a metal spring. The metal spring can be arranged in multiples, wherein a metal spring can be arranged at each end of the ultrasonic vibration rubber pressure wheel 23, and one end of the metal spring at the two ends is connected to the mounting frame 21, and the other end is rotatably connected to the ultrasonic vibration rubber pressure wheel 23 through a connecting rod.

[0051] The anti-welding plugging module 2 integrates multiple functional components such as the front scraper 22, the ultrasonic vibration rubber pressure wheel 23, the rear scraper 24 and the oil return scraper 25. These components are arranged in sequence along the moving direction on the mounting frame 21 to form an efficient and compact working unit, which can also enable the first ink coating, ink pressing, the second ink coating and ink oil return to be connected in sequence, thereby greatly improving the efficiency of ink plugging.

[0052] It should be noted that the front scraper 22 and the rear scraper 24 of this embodiment are the same, both are rubber scrapers with a hardness of 75 degrees. The hardness of the ultrasonic vibration rubber pressure wheel 23 is 40-50 degrees. The oil return scraper 25 is an aluminum scraper with a hardness of 75 degrees.

[0053] In this embodiment, a plurality of air suction holes 11 are provided on the machine 1, and the plurality of air suction holes 11 are located below the plug hole bottom plate 3. Specifically, the air suction holes 11 can be sucked through a negative pressure platform (not shown in the figure).

[0054] During the plugging process, the ink may generate bubbles due to various reasons. If these bubbles remain in the hole, the quality of the plugging and the conductivity of the circuit will be seriously affected. By providing a plurality of suction holes 11 on the machine 1, and these suction holes 11 are located below the plugging bottom plate 3, a negative pressure area can be formed to effectively absorb and discharge the bubbles in the ink, thereby ensuring the density and bubble-free state of the ink in the hole. At the same time, it can also help the ink to be filled into the plugged hole faster to a certain extent.

[0055] Optionally, in a possible implementation, an annular limiting frame 6 is provided on the machine 1 , and the annular limiting frame 6 is arranged around the outer circumference of the plug hole bottom plate 3 .

[0056] In the above technical solution, the design of the annular limit frame 6 provides a precise positioning and fixing structure for the plugging bottom plate 3. During the plugging operation, the plugging bottom plate 3 needs to remain stable and motionless to ensure that the ink can be accurately filled into each hole. The annular limit frame 6 can effectively limit the movement of the plugging bottom plate 3 by surrounding the outer circumference of the plugging bottom plate 3, thereby improving the stability and accuracy of the operation. In addition, during the ink coating and plugging process, the ink may overflow from the plugging area due to uneven coating or uneven pressure. The presence of the annular limit frame 6 can act as a barrier to prevent the overflowing ink from flowing to other parts of the machine 1 or contaminating other components.

[0057] In the description of the present invention, it should be understood that terms such as "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0058] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0059] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for plugging holes in a circuit board with solder mask ink, characterized in that: The following steps are involved: S1: manufacturing a plugging hole base plate and a plugging hole screen, processing the corresponding plugging hole base plate and plugging hole screen according to the size and position of the hole to be plugged on the circuit board; S2: Applying ink for the first time, placing the circuit board between the plugging bottom plate and the plugging screen, and applying the ink from the plugging screen to the holes to be plugged; S3: Pressing ink to further squeeze the ink into the hole to be plugged, so that the ink sinks to the lower part of the hole to be plugged; S4: applying ink for the second time, applying the ink from the plugging screen to the upper part of the hole to be plugged, so as to completely fill the hole to be plugged; S5: Ink returns to the oil tank and scrapes off excess ink.

2. The circuit board solder mask ink plugging method according to claim 1, characterized in that: The plugging hole screen is made of an aluminum sheet, on which screen holes corresponding to the holes to be plugged are arranged, and the aperture of the screen holes is equal to or smaller than the aperture of the holes to be plugged by 1-3 mil.

3. The circuit board solder mask ink plugging method according to claim 1, characterized in that: The plugging bottom plate is provided with a bottom plate hole corresponding to the hole to be plugged, and the hole diameter of the bottom plate hole is 4-6 mil larger than the hole diameter of the hole to be plugged.

4. The circuit board solder mask ink plugging method according to claim 1, characterized in that: In the step S2, before the first application of ink, the circuit board is first subjected to solder mask pre-treatment: a micro-etching solution is used in combination with volcanic ash to roughen the surface of the circuit board so that the surface of the circuit board forms a plowed shape.

5. The circuit board solder mask ink plugging method according to claim 1, characterized in that: The ink pressing method is as follows: an elastic ultrasonic vibration rubber pressure wheel is used to press the plugging screen, and at the same time, air is sucked from one side of the plugging bottom plate to the hole to be plugged, so as to squeeze the ink into the hole to be plugged.

6. The circuit board solder mask ink plugging method according to claim 1, characterized in that: The first application of ink and the second application of ink are applied by different scrapers.

7. A plugging device for a circuit board solder mask ink plugging method according to any one of claims 1 to 6, characterized in that: The invention comprises a machine platform and a solder-proof plugging hole module which can move relative to the machine platform. A plugging hole base plate, a circuit board to be plugged, and a plugging hole screen are sequentially stacked on the machine platform. The solder-proof plugging hole module can be attached to the surface of the plugging hole screen and slide.

8. The circuit board solder mask ink plugging device according to claim 7, characterized in that: The anti-welding plugging module includes a mounting frame, a driving module for driving the mounting frame to move, and a front scraper, an ultrasonic vibration rubber pressure wheel, a rear scraper and an oil return scraper which are arranged on the mounting frame and sequentially arranged along the moving direction of the mounting frame, and the ultrasonic vibration rubber pressure wheel is elastically connected to the mounting frame.

9. The circuit board solder mask ink plugging device according to claim 7, characterized in that: The machine platform is provided with a plurality of air suction holes, and the plurality of air suction holes are located below the plug hole bottom plate.

10. The circuit board solder mask ink plugging device according to claim 7, characterized in that: The machine platform is provided with an annular limiting frame, and the annular limiting frame is arranged around the outer periphery of the plug hole bottom plate.

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