PCB (Printed Circuit Board) solder mask spraying equipment and spraying method

Abstract

The invention relates to the technical field of PCB (Printed Circuit Board) production, and particularly discloses PCB solder mask spraying equipment and a spraying method. The equipment comprises a first spraying device, a turnover device, a second spraying device and a pre-baking device which are sequentially arranged, the spraying device comprises a conveying module, a first spraying gun, a second spraying gun and a third spraying gun, the conveying module is used for conveying the PCB, the first spraying gun is used for spraying first ink on the top face of the PCB and forming a first layer through standing, and the second spraying gun is used for spraying second ink on the first layer and forming a second layer through standing. The third spray gun is used for spraying third ink on the second layer and standing to form a third layer, and the viscosity of the first ink is greater than that of the second and third ink; the turnover device can turn over the PCB on the first spraying device and convey the PCB to the second spraying device; the pre-baking device can pre-bake the PCB on the second spraying device and move the PCB out. The equipment can simultaneously meet the oil thickness requirements of the circuit and the board surface, and solves the problems of ink entering and hole blocking.

Description

Technical Field

[0001] The invention relates to the technical field of PCB production, and in particular to PCB solder resist spraying equipment and a spraying method. Background Art

[0002] When printing circuit boards, a layer of ink is often applied to the surface of the PCB (Printed Circuit Board) to protect it from moisture, insulation and soldering. At present, the industry generally uses sprayers to spray solder mask ink on the PCB surface. The coating thickness and uniformity of solder mask ink are very important. However, due to the fluidity of liquid ink itself, there will be a vertical flow effect when spraying it on the PCB conductor line, which affects the coverage of the line conductor.

[0003] like Figure 1 and Figure 2 As shown, PCB800' includes substrate 820', outer copper 830' and circuit 810', outer copper 830' covers substrate 820', circuit 810' is arranged on the surface of outer copper 830' and located on both sides of substrate 820', and the solder resist ink coating operation is to use spray gun 700' to spray ink on the surface of PCB800', and form solder resist layer 900' after the ink is left to stand; the nozzle diameter of conventional spray gun 700' is 0.7-1.1 mm, the spray gun pressure is 3-6 kg, the Iwata cup viscosity of ink is 35-45 seconds, and one low viscosity spraying meets the finished solder resist oil thickness. When the conventional horizontal low pressure spraying method is used for the spraying operation of PCB800' thick copper plate (copper thickness ≧2OZ), it is difficult for solder resist layer 900' to meet the circuit oil thickness requirements and board surface oil thickness requirements at the same time. Among them, the line oil thickness requirement is that the line top oil thickness L≧10 microns and the line corner oil thickness M≧5 microns, and the board surface oil thickness requirement is that the board surface oil thickness N≦35 microns.

[0004] At present, conventional low-pressure spray ink has low viscosity, low atomization degree and large ink volume. Low-viscosity ink has poor oil-hanging ability at the corners of thick copper wires, which easily leads to the situation of thin oil and exposed copper. In addition, the openings on PCB800' are prone to oil accumulation, which easily leads to ink entering the holes. In actual production, if the board surface oil thickness N is controlled to be ≦35 microns, the circuit oil thickness is only 2-3 microns at this time, which is difficult to meet the circuit oil thickness requirements and is prone to false copper leakage quality defects; on the contrary, if the PCB800' is controlled to meet the circuit oil thickness requirements, the corresponding board surface oil thickness N will exceed 45 microns, and at least half of the openings on PCB800' will have defects of ink entering the holes and ink blocking the holes.

[0005] The existing solution is to use multiple spraying methods to solve this problem, but this process seriously affects production efficiency, and frequent operations will increase the risk of scratches on the surface of PCB800'. At the same time, this process is only suitable for samples and small batch production, and cannot achieve mass production. Summary of the invention

[0006] The purpose of the present invention is to provide PCB solder resist spraying equipment and spraying method to simultaneously meet the oil thickness requirements of the circuit and the board surface, solve the problems of ink entering the hole and ink blocking the hole, and enable the PCB spraying solution to be industrialized on a large scale.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] PCB solder resist spraying equipment is used to process PCB, the PCB solder resist spraying equipment comprises a first spraying device, a flipping device, a second spraying device and a pre-baking device arranged in sequence along a conveying direction; the spraying device comprises a conveying module and a first spray gun, a second spray gun and a third spray gun arranged in sequence along the conveying direction, the conveying module is used to convey the PCB along the conveying direction, the first spray gun is used to spray a first ink on the top surface of the PCB, the first ink is left to stand for a first time to form a first layer, the second spray gun is used to spray a second ink on the first layer, the second ink is left to stand for a second time to form a second layer, the third spray gun is used to spray a third ink on the second layer, the third ink is left to stand for a third time to form a third layer, the viscosity of the first ink is greater than the viscosity of the second ink, and the viscosity of the first ink is greater than the viscosity of the third ink; the flipping device can flip the PCB on the first spraying device and convey it to the second spraying device; the pre-baking device can pre-bake the PCB on the second spraying device and move it out of the PCB solder resist spraying equipment.

[0009] As an optional technical solution for PCB solder mask spraying equipment, the first spray gun can move close to or away from the conveying module; and / or, the second spray gun can move close to or away from the conveying module; and / or, the third spray gun can move close to or away from the conveying module.

[0010] As an optional technical solution for PCB solder mask spraying equipment, the first spray gun is slidably connected to the conveying module along the moving direction; and / or, the second spray gun is slidably connected to the conveying module along the moving direction; and / or, the third spray gun is slidably connected to the conveying module along the moving direction, wherein the moving direction is perpendicular to the conveying direction.

[0011] As an optional technical solution for PCB solder mask spraying equipment, the operating speed of the first spray gun is greater than the operating speed of the second spray gun; and / or the operating speed of the first spray gun is greater than the operating speed of the third spray gun.

[0012] As an optional technical solution for PCB solder mask spraying equipment, the nozzle diameter of the first spray gun is smaller than the nozzle diameter of the second spray gun; and / or, the nozzle diameter of the first spray gun is smaller than the nozzle diameter of the third spray gun.

[0013] As an optional technical solution for PCB solder mask spraying equipment, the sum of the first ink sprayed by the first spray gun, the second ink sprayed by the second spray gun, and the third ink sprayed by the third spray gun is the ink application amount, the first ink sprayed by the first spray gun accounts for 40-60% of the ink application amount, the second ink sprayed by the second spray gun accounts for 20-30% of the ink application amount, and the third ink sprayed by the third spray gun accounts for 20-30% of the ink application amount.

[0014] As an optional technical solution for the PCB solder resist spraying equipment, in one of the spraying devices, the first spray gun and the second spray gun are spaced apart, and the second spray gun and the third spray gun are spaced apart.

[0015] As an optional technical solution for PCB solder mask spraying equipment, the spacing between the first spray gun and the second spray gun in the conveying direction is a first spacing, the spacing between the second spray gun and the third spray gun in the conveying direction is a second spacing, and the first spacing is equal to the second spacing.

[0016] As an optional technical solution for PCB solder mask spraying equipment, the spray gun pressure of the first spray gun is greater than the spray gun pressure of the second spray gun; and / or, the spray gun pressure of the first spray gun is greater than the spray gun pressure of the third spray gun.

[0017] The PCB solder resist spraying process, applied to the above-mentioned PCB solder resist spraying equipment, comprises the following steps:

[0018] S1: placing the PCB on the first spraying device, firstly using the first spray gun to spray the first ink on the top surface of the PCB back and forth for multiple times, leaving it to stand for the first time to form the first layer, then using the second spray gun to spray the second ink on the first layer back and forth for multiple times, leaving it to stand for the second time to form the second layer, and then using the third spray gun to spray the third ink on the top surface of the PCB back and forth for multiple times;

[0019] S2: using the flipping device to turn over the PCB and transfer it to the second spraying device;

[0020] S3: Repeat the ink spraying process of S1 in the second spraying device;

[0021] S4: pre-bake the PCB on the second spraying device horizontally and vertically using a pre-bake device, and then move the PCB out of the PCB solder resist spraying equipment.

[0022] Beneficial effects of the present invention:

[0023] The PCB solder resist spraying equipment realizes double-sided solder resist spraying of the PCB by setting a first spraying device, a flipping device and a second spraying device, and the spraying device is equipped with three spray guns to spray different viscosity inks in sequence, thereby improving production efficiency and spraying quality, so that the ink can be sprayed layer by layer, and the rapid and continuous spraying of multi-layer solder resist can be realized, thereby improving the spraying efficiency. The first layer formed by the high-viscosity first ink sprayed by the first spray gun has a better line oil hanging ability, provides a stable base for the subsequent second and third layers, and improves the adhesion of the solder resist layer. The low-viscosity second ink and the third ink sprayed by the second and third spray guns continue to be sprayed on the first layer, ensuring the uniformity and consistency of the multi-layer solder resist. The method of spraying three inks, namely, the high-viscosity first ink, the low-viscosity second ink and the low-viscosity third ink, in sequence can simultaneously meet the PCB line oil thickness requirements and the board surface oil thickness requirements during the spraying operation. At the same time, the solution of spraying the required surface ink thickness three times can reduce the wet film thickness of the spray gun each time, thereby reducing the risk of ink entering the hole and reducing the problem of ink entering the hole as much as possible.

[0024] In the existing conventional low-pressure spraying, only a single spray gun is provided in the corresponding spraying device to spray a single type of ink, and the processing of PCB requires multiple spraying and baking cycles. The PCB solder resist spraying equipment provided in this embodiment can realize a one-time spraying and baking processing scheme, which significantly improves the work efficiency and product quality compared with the conventional low-pressure spraying scheme, and also reduces the steps of spraying and baking, thereby effectively reducing the risk of scratches on the PCB surface.

[0025] The above improvements, combined with the setting of the conveying module, realize the smooth conveying of PCBs, which helps to improve the degree of automation of the production process and reduce the workload of operators. The automatic turning over of the PCB can be achieved through the flipping device, so that both sides can be evenly sprayed and treated, reducing manual intervention and meeting the process requirements. The pre-baking device can be connected to the second spraying device to pre-bake the sprayed PCB to achieve a seamless transition, provide convenience for subsequent processing, improve the performance of the solder mask layer, and ensure the stability and static effect of the PCB during the spraying process. The above design makes the design of PCB solder mask spraying equipment accurate, efficient and stable, realizes efficient and continuous solder mask spraying treatment of PCBs, improves production efficiency and product quality, reduces production costs, and enables large-scale industrialization of PCB spraying solutions, which has broad application prospects and market value.

[0026] The PCB solder resist spraying process uses multiple reciprocating spraying and static standing to ensure that each layer of solder resist ink can be evenly covered and tightly combined, thereby improving the oil-hanging and uniformity of the solder resist layer, reducing defects and scrap rates caused by uneven spraying, and the first layer formed by the first ink sprayed by the first spray gun has a higher thickness and viscosity, which can effectively enhance the adhesion and uniformity of subsequent spraying. The PCB is turned over by a flipping device and sprayed again, so that the ink is evenly sprayed and processed on both sides of the PCB, improving the integrity and functionality of the PCB, without the need for additional processes, and simplifying the operation process. Repeating the ink spraying process in the second spraying device ensures that the spraying quality of the solder resist on both sides and the thickness of the solder resist layer are consistent, improving product quality and aesthetics. The pre-baking device can quickly and effectively pre-bake the PCB, improve production efficiency, shorten the production cycle, and the pre-baking process can also improve the wear resistance, heat resistance and other properties of the solder resist layer. At the same time, the increase in horizontal pre-baking can effectively reduce the flow and dripping of ink, and the vertical pre-baking helps reduce the risk of PCB bending due to gravity, thereby improving the appearance quality of the PCB. The above-mentioned PCB solder mask spraying process is simple, efficient, stable and reliable, which reduces production costs and scrap rates, meets the high efficiency and high quality requirements in modern electronic manufacturing, and has significant economic benefits and technical advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the local structure of the existing PCB and solder mask;

[0028] Figure 2 It is a schematic diagram of the structure of an existing spray gun, PCB and solder mask;

[0029] Figure 3 It is a structural schematic diagram of a PCB solder resist spraying device provided by an embodiment of the present invention;

[0030] Figure 4is a schematic structural diagram of a spraying device provided in an embodiment of the present invention;

[0031] Figure 5 It is a schematic structural diagram of a spraying device, a PCB and a solder resist layer provided in an embodiment of the present invention;

[0032] Figure 6 It is a schematic diagram of the partial structure of a PCB and a solder resist layer provided in an embodiment of the present invention.

[0033] Figure 1 and Figure 2 middle:

[0034] 700', spray gun; 800', PCB; 810', circuit; 820', substrate; 830', outer copper layer; 900', solder mask;

[0035] Figures 3 to 6 middle:

[0036] X, transmission direction; Y, moving direction;

[0037] 100. Turning device;

[0038] 200, spraying device; 210, first spray gun; 220, second spray gun; 230, third spray gun; 240, conveying module;

[0039] 300, pre-baking device;

[0040] 800, PCB; 820, substrate; 830, outer copper;

[0041] 900, solder mask layer; 910, first layer; 920, second layer; 930, third layer. DETAILED DESCRIPTION

[0042] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. 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 cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature "above", "above" and "above" the second feature include the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature include the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0046] like Figures 3 to 6As shown, this embodiment provides a PCB solder resist spraying device for processing PCB800, and the PCB solder resist spraying device includes a first spraying device 200, a flipping device 100, a second spraying device 200 and a pre-baking device 300 arranged in sequence along the conveying direction X; the spraying device 200 includes a conveying module 240 and a first spray gun 210, a second spray gun 220 and a third spray gun 230 arranged in sequence along the conveying direction X, the conveying module 240 is used to convey the PCB800 along the conveying direction X, the first spray gun 210 is used to spray a first ink on the top surface of the PCB800, and the first ink is left to stand for a first time to form a first The first layer 910 is formed by spraying a second ink on the second spraying device 200, and the second ink is left to stand for a second time to form a second layer 920. The third layer 910 is formed by spraying a third ink on the second layer 920, and the third ink is left to stand for a third time to form a third layer 930. The viscosity of the first ink is greater than that of the second ink, and the viscosity of the first ink is greater than that of the third ink. The flipping device 100 can flip the PCB 800 on the first spraying device 200 and transfer it to the second spraying device 200. The pre-baking device 300 can pre-bake the PCB 800 on the second spraying device 200 and move it out of the PCB solder mask spraying equipment.

[0047] For ease of expression, it is defined below that the first layer 910 , the second layer 920 and the third layer 930 stacked in sequence constitute the solder resist layer 900 ; the PCB 800 includes a substrate 820 and an outer copper layer 830 , the outer copper layer 830 covers the substrate 820 , and the first layer 910 is formed on the outer copper layer 830 .

[0048] The PCB solder resist spraying equipment realizes double-sided solder resist spraying of PCB800 by setting a first spraying device 200, a flipping device 100 and a second spraying device 200, and the spraying device 200 is equipped with three spray guns to spray different viscosity inks in sequence, thereby improving production efficiency and spraying quality, so that the ink can be sprayed layer by layer, and the rapid and continuous spraying of multi-layer solder resist can be realized, thereby improving spraying efficiency. The first layer 910 formed by the high-viscosity first ink sprayed by the first spray gun 210 has a better line oil hanging ability, provides a stable base for the subsequent second layer 920 and the third layer 930, and improves the adhesion of the solder resist layer 900. The low-viscosity second ink and the third ink sprayed by the second spray gun 220 and the third spray gun 230 continue to spray on the first layer 910, ensuring the uniformity and consistency of the multi-layer solder resist. The method of spraying three inks, namely, the high-viscosity first ink, the low-viscosity second ink and the low-viscosity third ink, in sequence can simultaneously meet the PCB800 line oil thickness requirements and the board surface oil thickness requirements during the spraying operation. At the same time, the solution of spraying the required surface ink thickness three times can reduce the wet film thickness of the spray gun each time, thereby reducing the risk of ink entering the holes and minimizing the problem of ink entering the holes.

[0049] In the existing conventional low-pressure spraying, only a single spray gun is provided in the corresponding spraying device to spray a single type of ink, and the processing of PCB requires multiple spraying and baking cycles. The PCB solder resist spraying equipment provided in this embodiment can realize a one-time spraying and baking processing scheme, which significantly improves the work efficiency and product quality compared to the conventional low-pressure spraying scheme, and also reduces the steps of spraying and baking, thereby effectively reducing the risk of scratches on the surface of PCB800.

[0050] The above improvements combined with the setting of the conveying module 240 realize the smooth conveyance of PCB800, which helps to improve the automation degree of the production process and reduce the workload of operators. The automatic turning over of PCB800 can be realized by the flipping device 100, so that both sides can be evenly sprayed and processed, reducing manual intervention and meeting the process requirements. The pre-baking device 300 can be docked with the second spraying device 200, so as to pre-bake the sprayed PCB800 to achieve a seamless transition, provide convenience for subsequent processing, improve the performance of the solder mask layer 900, and ensure the stability and static effect of PCB800 during the spraying process. The above design makes the design of PCB solder mask spraying equipment accurate, efficient and stable, realizes efficient and continuous solder mask spraying treatment of PCB800, improves production efficiency and product quality, reduces production costs, and enables the PCB800 spraying solution to be industrialized on a large scale, with broad application prospects and market value.

[0051] In this embodiment, the Iwata Cup viscosity of the first ink is 80.00-100.00 seconds, the Iwata Cup viscosity of the second ink is 35.00-45.00 seconds, and the Iwata Cup viscosity of the third ink is 35.00-45.00 seconds.

[0052] In one implementation of this embodiment, the first spray gun 210 can move close to or away from the conveying module 240 ; the second spray gun 220 can move close to or away from the conveying module 240 ; and the third spray gun 230 can move close to or away from the conveying module 240 .

[0053] The first spray gun 210, the second spray gun 220 and the third spray gun 230 can move closer to or away from the conveying module 240. This design allows the spray guns to adjust their positions according to actual needs, making spraying more flexible and adaptable to PCBs 800 of different sizes and shapes, thereby improving the flexibility and versatility of the PCB solder mask spraying equipment. At the same time, the movable design of the spray gun helps to achieve a more uniform spraying effect and reduce ink waste.

[0054] In other implementations of this embodiment, only the first spray gun 210 is limited to be able to move close to or away from the conveying module 240 , or only the third spray gun 230 is limited to be able to move close to or away from the conveying module 240 .

[0055] In one implementation of this embodiment, the first spray gun 210 is slidably connected to the conveying module 240 along the moving direction Y; the second spray gun 220 is slidably connected to the conveying module 240 along the moving direction Y; the third spray gun 230 is slidably connected to the conveying module 240 along the moving direction Y, wherein the moving direction Y is perpendicular to the conveying direction X.

[0056] The design of the spray gun slidingly connected to the conveying module 240 along the moving direction Y allows the spray gun to perform spraying operations more stably, thereby achieving precise control of the spraying on the surface of the PCB 800, improving the uniformity and accuracy of the spraying, and reducing the error caused by the movement of the PCB solder mask spraying equipment. At the same time, the limitation that the moving direction Y is perpendicular to the conveying direction X also allows the spray gun to control the spraying range more accurately, which helps to improve the accuracy of the spraying.

[0057] In other implementations of this embodiment, only at most two of the first spray gun 210 , the second spray gun 220 and the third spray gun 230 are slidably connected to the conveying module 240 along the moving direction Y.

[0058] In one implementation of this embodiment, the operating speed of the first spray gun 210 is greater than the operating speed of the second spray gun 220; the operating speed of the first spray gun 210 is greater than the operating speed of the third spray gun 230. Specifically, the operating speed of the first spray gun 210 is 2200.00-2500.00 mm per second, the operating speed of the second spray gun 220 is 1800.00-2000.00 mm per second, and the operating speed of the third spray gun 230 is 1500.00-1700.00 mm per second.

[0059] By limiting the running speed of the spray gun, different spray guns have different running speeds, which helps to independently control the spray thickness and uniformity of each layer of ink, improving product quality and reliability. At the same time, by adjusting the running speed of the spray gun, different layers of ink can be sprayed evenly, thereby improving work efficiency.

[0060] In other implementations of this embodiment, only the operating speed of the first spray gun 210 is limited to be greater than the operating speed of the second spray gun 220 ; or only the operating speed of the first spray gun 210 is limited to be greater than the operating speed of the third spray gun 230 .

[0061] In one implementation of this embodiment, the nozzle diameter of the first spray gun 210 is smaller than the nozzle diameter of the second spray gun 220 ; the nozzle diameter of the first spray gun 210 is smaller than the nozzle diameter of the third spray gun 230 .

[0062] The nozzle calibers of the first spray gun 210, the second spray gun 220 and the third spray gun 230 are different, which is conducive to controlling the flow and distribution of the ink, making the spraying of each layer of ink more delicate and uniform, and helping to improve the overall quality of the solder mask layer 900. At the same time, nozzles of different calibers realize the spraying of inks with different ink viscosities, spraying pressures and solder mask thicknesses, meeting the multi-level requirements of the solder mask layer 900.

[0063] Specifically, the nozzle diameter of the first spray gun 210 is 0.13-0.23 mm, the nozzle diameter of the second spray gun 220 is 0.70 mm, and the nozzle diameter of the third spray gun 230 is 0.70 mm.

[0064] Under high pressure, the small-diameter nozzle of the first spray gun 210 can highly atomize the high-viscosity first ink, and preferentially deposit a uniform layer of solder mask ink on the board surface and line corners of PCB800. This layer of solder mask ink has poor fluidity and can provide and supplement better oil hanging ability for the thick copper wire corner line top.

[0065] In other implementations of this embodiment, only the nozzle diameter of the first spray gun 210 is limited to be smaller than the nozzle diameter of the second spray gun 220 ; or only the nozzle diameter of the first spray gun 210 is limited to be smaller than the nozzle diameter of the third spray gun 230 .

[0066] In this embodiment, the sum of the first ink sprayed by the first spray gun 210, the second ink sprayed by the second spray gun 220, and the third ink sprayed by the third spray gun 230 is the ink deposit amount, the first ink sprayed by the first spray gun 210 accounts for 40-60% of the ink deposit amount, the second ink sprayed by the second spray gun 220 accounts for 20-30% of the ink deposit amount, and the third ink sprayed by the third spray gun 230 accounts for 20-30% of the ink deposit amount. Specifically, the first ink sprayed by the first spray gun 210 accounts for 40% of the ink deposit amount, the second ink sprayed by the second spray gun 220 accounts for 30% of the ink deposit amount, and the third ink sprayed by the third spray gun 230 accounts for 30% of the ink deposit amount. The sum of the ink deposited by the first spray gun 210, the second spray gun 220, and the third spray gun 230 is 100% of the set ink deposit amount, and the oiliness of the ink is achieved while ensuring the apparent leveling.

[0067] By reasonably allocating the ink spraying ratios of the first spray gun 210, the second spray gun 220 and the third spray gun 230, the uniformity and integrity of each layer of ink can be ensured, the optimized structure and precise control of the solder mask layer 900 can be achieved, and the consistency and stability of the PCB 800 can be improved.

[0068] In one implementation of this embodiment, the spray gun pressure of the first spray gun 210 is greater than the spray gun pressure of the second spray gun 220; the spray gun pressure of the first spray gun 210 is greater than the spray gun pressure of the third spray gun 230. Specifically, the spray gun pressure of the first spray gun 210 is 60.00-100.00 kg, the spray gun pressure of the second spray gun 220 is 3.00-6.00 kg, and the spray gun pressure of the third spray gun 230 is 3.00-6.00 kg.

[0069] This design enables the first spray gun 210 to more effectively spray high-viscosity ink onto the surface of the PCB 800, thereby improving the uniformity and adhesion of the high-viscosity ink spraying. Through the above design of limiting the spray gun pressure, the ink spraying amount can be precisely controlled, ensuring the uniform distribution and effective spraying of the ink, improving the spraying effect and product performance, and further improving the quality and accuracy of the processing.

[0070] In other implementations of this embodiment, only the spray gun pressure of the first spray gun 210 is limited to be greater than the spray gun pressure of the second spray gun 220 ; or only the spray gun pressure of the first spray gun 210 is limited to be greater than the spray gun pressure of the third spray gun 230 .

[0071] The process route of spraying high-viscosity ink once and then spraying low-viscosity ink twice is selected because the high-viscosity first ink has a low cast rate at the opening of PCB800. The high-viscosity first ink is used for a small amount of multiple spraying operations to better coat the first ink and improve the line edge oiling of the first layer 910. Spraying only the high-viscosity first ink can easily lead to a rough and granular appearance on the surface of PCB800, so it is necessary to supplement the low-viscosity ink spraying with good flowability twice to make the solder mask surface smooth and flat. The above process route can simultaneously meet the line oil thickness requirements and board surface oil thickness requirements of PCB800 thick copper board.

[0072] At the same time, the above process route can also solve the problems of ink entering the hole and ink blocking the hole. The traditional spraying method is to complete the spraying in one time, and the spraying pressure and ink spraying amount are greater than the current three-time spraying, and the risk of ink entering the hole and blocking the hole is extremely high. The above process route enables high-viscosity ink to be sprayed at high pressure. The high-viscosity ink has a high degree of atomization under high pressure and can be evenly covered on the surface of PCB800. High-pressure spraying of high-viscosity ink can also effectively prevent high-viscosity ink from blocking the nozzle; at the same time, it also reduces the proportion of low-viscosity ink in the amount of ink, resulting in a decrease in the probability of blocking, thereby achieving the purpose of reducing the spraying pressure and ink amount, reducing the risk of ink entering the hole, and reducing the proportion of ink entering the hole and blocking the hole, thereby avoiding the blockage of the openings with a hole diameter of less than 0.20 mm on PCB800.

[0073] Illustratively, in a spraying device 200 , the first spray gun 210 and the second spray gun 220 are spaced apart from each other, and the second spray gun 220 and the third spray gun 230 are spaced apart from each other.

[0074] Reasonable spray gun interval setting allows each spray gun to work independently without interfering with each other, improving the efficiency and accuracy of spraying. The above improvements help to achieve uniform spraying and coverage of ink, avoid missed spraying and re-spraying, and help improve product quality.

[0075] Further, the distance between the first spray gun 210 and the second spray gun 220 in the conveying direction X is a first distance, the distance between the second spray gun 220 and the third spray gun 230 in the conveying direction X is a second distance, and the first distance is equal to the second distance.

[0076] By setting the same spacing between the first spray gun 210 and the second spray gun 220 and between the second spray gun 220 and the third spray gun 230 in the conveying direction X, it is possible to ensure that the spraying positions of the two layers of ink correspond accurately, reducing the difficulty of the conveying module 240 to adjust the position of the PCB 800, which helps to improve the accuracy and automation of the solder resist spraying process. At the same time, the equal spacing is also conducive to controlling the drying time and distribution of the ink, improving the stability and continuity of the spraying process, and helping to improve production efficiency and product quality.

[0077] This embodiment also provides a PCB solder resist spraying process, which is applied to the above-mentioned PCB solder resist spraying equipment, and includes the following steps:

[0078] Step 1: Place PCB800 on the first spraying device 200, first use the first spray gun 210 to spray the first ink on the top surface of PCB800 back and forth for multiple times, let it stand for a first time to form a first layer 910, then use the second spray gun 220 to spray the second ink on the first layer 910 back and forth for multiple times, let it stand for a second time to form a second layer 920, and then use the third spray gun 230 to spray the third ink on the top surface of PCB800 back and forth for multiple times.

[0079] Step 2: Use the flipping device 100 to turn over the PCB 800 and transfer it to the second spraying device 200 .

[0080] Step 3: Repeat the ink spraying process of step 1 in the second spraying device 200 .

[0081] Step 4: Use the pre-baking device 300 to perform horizontal and vertical pre-baking on the PCB 800 on the second spraying device 200, and then move the PCB 800 out of the PCB solder resist spraying equipment.

[0082] The PCB solder resist spraying process can evenly cover and tightly combine each layer of solder resist ink through multiple reciprocating spraying and standing, improve the oil-hanging property and uniformity of the circuit of the solder resist layer 900, reduce the defects and scrap rate caused by uneven spraying, and the first layer 910 formed by the first ink sprayed by the first spray gun 210 has a higher thickness and viscosity, which can effectively enhance the adhesion and uniformity of subsequent spraying. The flip device 100 is used to turn the PCB800 over and spray it again, so that the ink is evenly sprayed and processed on both sides of the PCB800, which improves the integrity and functionality of the PCB800, does not require additional processes, and simplifies the operation process. Repeating the ink spraying process in the second spraying device 200 ensures that the spraying quality of the solder resist on both sides and the thickness of the solder resist layer 900 are consistent, and improves the product quality and aesthetics. The pre-baking device 300 can quickly and effectively pre-bake the PCB800, improve production efficiency, shorten the production cycle, and the pre-baking process can also improve the wear resistance, heat resistance and other properties of the solder resist layer 900. At the same time, the increase in horizontal pre-baking can effectively reduce the flow and dripping of ink, and the vertical pre-baking helps to reduce the risk of bending of PCB800 due to gravity, thereby improving the appearance quality of PCB800. The above-mentioned PCB solder resist spraying process is simple, efficient, stable and reliable, which reduces production costs and scrap rates, meets the high efficiency and high quality requirements in modern electronic manufacturing, and has significant economic benefits and technical advantages.

[0083] By using the above-mentioned PCB solder resist spraying process, a layer of high-viscosity ink can be preferentially deposited by high-pressure atomization at the edge of the hole of PCB800. Under the gravity of the first ink and the interfacial force traction of the first ink itself, the operation of spraying low-viscosity ink is not easy to penetrate and gather into the hole, so it can effectively improve the blocking rate of small-diameter through holes. The thickness of the solder resist layer 900 on the PCB800 treated with solder resist spraying using the above-mentioned process route is the same as the thickness of the solder resist layer 900 on the PCB800 treated with traditional one-time low-viscosity spraying. The line oil hanging capacity is 30%-40% higher than the traditional one-time low-viscosity spraying treatment, and can effectively reduce the probability of ink entering the hole and blocking the hole.

[0084] In other implementations of this embodiment, the number of spraying of the low-viscosity ink is greater than two times, and the number of spray guns other than the first spray gun 210 is the same as the number of spraying of the low-viscosity ink. The number of spraying of the low-viscosity ink is determined by personnel in this field according to actual engineering practices, and the determination method is common knowledge in this field and will not be elaborated herein.

[0085] In this embodiment, the first time is 7.00 seconds, and the second time is 7.00 seconds. Specifically, the first spacing and the second spacing are both 350.00 millimeters, and the conveying speed of the conveying module 240 for the PCB 800 is 4.00-5.00 meters per minute.

[0086] The above limitation ensures that the ink remains on the board for at least 7.00 seconds, ensuring that the ink is fully allowed to stand. The standing operation has the ability to eliminate bubbles in the solder mask layer 900 and naturally dry the ink, significantly improving ink pinholes and flatness defects.

[0087] In this embodiment, a sensor is provided at the entrance of the spraying device 200, and the sensor can sense the PCB800 which is 550.00 mm away from the first spray gun 210 in the conveying direction X, and then the first spray gun 210, the second spray gun 220 and the third spray gun 230 start to work at different speeds at the same time. The above design can not only ensure the stability of the operation of the PCB solder resist spraying equipment, but also perform multiple small-scale spraying operations for high-viscosity inks to ensure the uniformity of the oil hanging on the lines on the PCB800. For low-viscosity spraying operations, the transmission speed of the transmission module 240 can be slowed down to ensure the flatness of the second layer 920 and the third layer 930. The above process ensures the uniformity of the ink sprayed on the board surface without wasting the sprayed ink. Only one operator is needed to operate the entire PCB solder resist spraying equipment, and continuous automatic operation can be realized. Compared with the previous manual production efficiency, it is increased by more than 50%, thereby ensuring quality while improving work efficiency.

[0088] Furthermore, the spraying device 200 is also provided with an ink supply assembly, which is used to modulate the 100% viscosity ink into the first ink, the second ink and the third ink with different viscosities, and supply them to the corresponding spray guns.

[0089] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. PCB solder resist spraying equipment, used for processing PCB (800), characterized in that: The PCB solder resist spraying equipment comprises a first spraying device (200), a turning device (100), a second spraying device (200) and a pre-baking device (300) which are sequentially arranged along a conveying direction (X); The spraying device (200) comprises a conveying module (240) and a first spray gun (210), a second spray gun (220) and a third spray gun (230) which are sequentially arranged along the conveying direction (X), the conveying module (240) being used to convey the PCB (800) along the conveying direction (X), the first spray gun (210) being used to spray a first ink on the top surface of the PCB (800), the first ink being left to stand for a first time to form a first layer (910), the second spray gun (220) being used to spray a second ink on the first layer (910), the second ink being left to stand for a second time to form a second layer (920), the third spray gun (230) being used to spray a third ink on the second layer (920), the third ink being left to stand to form a third layer (930), the viscosity of the first ink being greater than the viscosity of the second ink, and the viscosity of the first ink being greater than the viscosity of the third ink; The flipping device (100) is capable of flipping the PCB (800) on the first spraying device (200) and transferring it to the second spraying device (200); The pre-baking device (300) is capable of pre-baking the PCB (800) on the second spraying device (200) and removing the PCB solder resist spraying equipment.

2. The PCB solder resist spraying equipment according to claim 1, characterized in that: The first spray gun (210) is capable of moving closer to or farther from the transfer module (240); and / or, The second spray gun (220) is capable of moving closer to or farther from the conveying module (240); and / or, The third spray gun (230) is capable of moving closer to or farther from the transfer module (240).

3. The PCB solder resist spraying equipment according to claim 2, characterized in that: The first spray gun (210) is slidably connected to the conveying module (240) along a moving direction (Y); and / or, The second spray gun (220) is slidably connected to the conveying module (240) along the moving direction (Y); and / or, The third spray gun (230) is slidably connected to the conveying module (240) along the moving direction (Y), wherein the moving direction (Y) is perpendicular to the conveying direction (X).

4. The PCB solder resist spraying equipment according to claim 3, characterized in that: The operating speed of the first spray gun (210) is greater than the operating speed of the second spray gun (220); and / or, The operating speed of the first spray gun (210) is greater than the operating speed of the third spray gun (230).

5. The PCB solder resist spraying equipment according to claim 4, characterized in that: The nozzle diameter of the first spray gun (210) is smaller than the nozzle diameter of the second spray gun (220); and / or, The nozzle diameter of the first spray gun (210) is smaller than the nozzle diameter of the third spray gun (230).

6. The PCB solder resist spraying equipment according to claim 1, characterized in that: The sum of the first ink sprayed by the first spray gun (210), the second ink sprayed by the second spray gun (220), and the third ink sprayed by the third spray gun (230) is the ink deposit amount, the first ink sprayed by the first spray gun (210) accounts for 40-60% of the ink deposit amount, the second ink sprayed by the second spray gun (220) accounts for 20-30% of the ink deposit amount, and the third ink sprayed by the third spray gun (230) accounts for 20-30% of the ink deposit amount.

7. The PCB solder resist spraying equipment according to claim 1, characterized in that: In a spraying device (200), the first spray gun (210) and the second spray gun (220) are arranged at intervals, and the second spray gun (220) and the third spray gun (230) are arranged at intervals.

8. The PCB solder resist spraying equipment according to claim 7, characterized in that: The distance between the first spray gun (210) and the second spray gun (220) in the conveying direction (X) is a first distance, the distance between the second spray gun (220) and the third spray gun (230) in the conveying direction (X) is a second distance, and the first distance is equal to the second distance.

9. The PCB solder resist spraying equipment according to any one of claims 1 to 8, characterized in that: The spray gun pressure of the first spray gun (210) is greater than the spray gun pressure of the second spray gun (220); and / or, The spray gun pressure of the first spray gun (210) is greater than the spray gun pressure of the third spray gun (230). 10.PCB solder resist spraying process, characterized in that: The PCB solder resist spraying device applied to any one of claims 1 to 9 comprises the following steps: S1: placing the PCB (800) on the first spraying device (200), firstly using the first spray gun (210) to spray the first ink on the top surface of the PCB (800) back and forth for multiple times, leaving it to stand for the first time to form the first layer (910), then using the second spray gun (220) to spray the second ink on the first layer (910) back and forth for multiple times, leaving it to stand for the second time to form the second layer (920), and then using the third spray gun (230) to spray the third ink on the top surface of the PCB (800) back and forth for multiple times; S2: using the turning device (100) to turn over the PCB (800) and transfer it to the second spraying device (200); S3: Repeat the ink spraying process of S1 in the second spraying device (200); S4: using a pre-baking device (300) to perform horizontal pre-baking and vertical pre-baking on the PCB (800) on the second spraying device (200), and then moving the PCB (800) out of the PCB solder resist spraying equipment.

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