Multistage filtering system for low-pressure spraying of PCB (Printed Circuit Board)

Abstract

The utility model relates to the technical field of printing ink treatment, and provides a PCB low-pressure spraying multi-stage filtering system which comprises a sealing barrel and filters, the sealing barrel is communicated with the filters, each filter is provided with two connectors capable of being connected in series, and when multiple filters are connected in series, the two connectors on each filter are communicated; an inner cavity and an outer cavity are formed in the filter, the inner cavity is communicated with the outer cavity through a cylindrical filter screen, an input pipe and an output pipe are further arranged in the filter, the input pipe is communicated with the inner cavity, the output pipe is communicated with the outer cavity, and the input pipe and the output pipe are connected with the two connectors respectively; a flow guide part is installed in the cylindrical filter screen, a plurality of flow channels are evenly distributed on the side wall of the flow guide part, and a protruding part is arranged between every two flow channels. According to the multi-stage filtering system, printing ink is uniformly filtered through the cylindrical filter screen and the flow guide piece, foreign matter is prevented from blocking the filter screen, and meanwhile the filter can be connected in series to achieve multi-stage filtering.

Description

Technical Field

[0001] This utility model relates to the field of ink processing technology, and in particular to a multi-stage filtration system for low-pressure spraying of PCBs. Background Technology

[0002] Low-pressure spraying technology for PCBs is a widely used technology in modern PCB manufacturing. It uses high-pressure air to form mist particles, which are then sprayed evenly onto the PCB board. It is mainly used for spraying solder resist ink.

[0003] The inks used in low-pressure PCB spraying technology may contain tiny foreign particles, especially recycled inks, which are more prone to contamination. This can cause nozzle clogging or foreign matter on the PCB surface during spraying. Currently, most ink filtration equipment's filters are easily clogged by foreign matter after a period of use, reducing the filtration rate and requiring frequent filter replacements. This results in poor durability and impacts production efficiency. Utility Model Content

[0004] This invention addresses the shortcomings of existing technologies by providing a multi-stage filtration system for low-pressure spraying of PCBs. By combining a flow guide with a cylindrical filter screen, ink can be filtered evenly, preventing filter screen clogging. Furthermore, multiple filters can be connected in series to achieve multi-stage filtration.

[0005] This utility model provides a multi-stage filtration system for low-pressure spraying of PCBs, including a sealed barrel and a filter. The sealed barrel is connected to the filter, and the filter has two interfaces that can be connected in series. When multiple filters are connected in series, they are connected through the two interfaces on each filter. The filter has an inner cavity and an outer cavity, which are connected to each other through a cylindrical filter screen. The filter also has an input pipe and an output pipe. The input pipe is connected to the inner cavity, and the output pipe is connected to the outer cavity. The input pipe and the output pipe are respectively connected to the two interfaces. A flow guide is installed in the cylindrical filter screen. Multiple flow channels are evenly distributed on the side wall of the flow guide, and a protrusion is provided between every two flow channels.

[0006] The sealed container holds the stirred ink for delivery into the filter. Two ports on the filter are for ink input and output, respectively, and can be used to connect multiple filters in series for multi-stage filtration. The filter's inner and outer chambers are separated by a cylindrical filter screen. The top of the inner chamber connects to the input pipe, and the top of the outer chamber connects to the output pipe. Ink flows in from the top of the cylindrical filter screen, is filtered out, and then enters the output pipe connected at the top from the outer chamber. Multiple protrusions on the sidewall of the flow guide form multiple flow channels. The flow guide is vertically installed in the cylindrical filter screen, which diverts the ink flowing into the screen, allowing it to pass evenly from all directions. This disperses foreign particles in the ink, preventing localized accumulation and clogging on the filter screen.

[0007] In a preferred embodiment of this invention, the filter includes a fixing part and a disassembly part, the fixing part and the disassembly part are detachably connected, and a sealing gasket is provided between the fixing part and the disassembly part.

[0008] The output tube is located in the fixed part, and the two interfaces mentioned above are located on symmetrical sides of the fixed part. The inner cavity and outer cavity are located in the disassembly part. The fixed part can be fixedly installed on the bracket, and the disassembly part is connected to the fixed part by bolts or threads. It can be disassembled at any time to replace the cylindrical filter screen or flow guide. At the same time, the sealing gasket can block the connection between the fixed part and the disassembly part to prevent ink leakage and contamination of the working environment.

[0009] In a preferred embodiment of this invention, the sealed container is further connected to a pressurizing device, which is used to input air into the sealed container.

[0010] Originally, the ink in the sealed container flowed freely into the filter by gravity, and the filter relied on the liquid pressure of the ink for filtration. This resulted in a slow flow rate and low filtration efficiency. By installing a pressurization device, air pressure can be used to accelerate the flow of ink, thereby enhancing the filtration capacity.

[0011] In a preferred embodiment of this invention, the sealing barrel and the filter are connected by a one-way valve, and the flow direction of the one-way valve is from the sealing barrel into the filter.

[0012] A one-way valve is connected to the bottom of the sealed container. The pressurizing device drives gas into the sealed container, which is squeezed above the ink and forced to flow downward to the one-way valve. The one-way valve controls the flow direction, allowing the ink to flow into the filter in one direction and preventing backflow.

[0013] In a preferred embodiment of this invention, the one-way valve is a pneumatically controlled one-way valve, which is connected to the pressurizing device.

[0014] The air pressure provided by the pressurizing device controls the opening and closing of the pneumatic check valve. When the pressurizing device pressurizes the sealed container, it simultaneously supplies gas to the pneumatic check valve, opening the passage within the valve and allowing the ink to flow. When the pressurizing device stops pressurizing, the pneumatic check valve discharges the gas supplied by the pressurizing device, closing the internal passage and preventing backflow.

[0015] In a preferred embodiment of this invention, the multi-stage filtration system is provided with a plurality of filters, each of which is provided with a cylindrical filter screen, and the pore sizes of the plurality of cylindrical filter screens are arranged in descending order.

[0016] By connecting multiple filters in series, the ink passes through cylindrical filter screens with large, medium and small pore sizes, filtering out foreign particles layer by layer, further purifying the ink, and thus reducing the probability of nozzle clogging or foreign matter appearing on the PCB board surface.

[0017] In a preferred embodiment of this invention, the sealed container includes a lid and a body, the lid and the body are detachably connected, the air supply pipe of the pressurizing device passes through the lid and connects to the body, and the body connects to the filter.

[0018] The separate design of the barrel body and the lid makes it easy to add ink. When the two are closed, they provide a sealed environment, which helps to prevent the ink from being contaminated by other substances and maintain the air pressure generated by the pressurizing device.

[0019] In a preferred embodiment of this invention, an anti-slip ring is provided on the outer side of the disassembly / assembly part.

[0020] The anti-slip ring is integrally molded with the disassembly part and is set around the disassembly part. This helps to increase the friction between the worker's hand and the disassembly part, making it easier for the worker to separate the disassembly part from the fixed part.

[0021] In a preferred embodiment of this invention, the top of the cylindrical filter screen is provided with multiple limiting components.

[0022] Multiple limiting components are used to ensure that there is a gap between the cylindrical filter screen and the cavity wall of the outer cavity, so that the filtered ink can pass through the gap to reach the input pipe. Furthermore, the upper surface of the multiple limiting components is lower than the opening of the cylindrical filter screen, ensuring that the cylindrical filter screen and the input pipe are tightly connected.

[0023] In a preferred embodiment of this invention, the pressurizing device is an air compressor.

[0024] The pressurization device can use commercially available air compressors or other air source devices to deliver high-pressure gas into the sealed container. This drives the ink along the transport path and speeds up its passage through the cylindrical filter, thereby improving production efficiency.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] This utility model provides a multi-stage filtration system for low-pressure PCB spraying, comprising a sealed container for holding ink and a filter for filtering the ink. The sealed container is connected to the filter through an interface to supply ink. The ink enters the inner cavity through the interface and the inlet pipe, and is guided and diverted into the flow channel by protrusions on the guide component, thereby dispersing and uniformly filtering the ink through the cylindrical filter screen. This prevents foreign matter in the ink from accumulating in localized areas of the cylindrical filter screen and causing blockage. The filtered ink enters the outer cavity and flows out through the outlet pipe and another interface. If another filter is connected in series through this interface, the above filtration process can be repeated to achieve multi-stage filtration and improve filtration accuracy. This design solves the problem of easy clogging in traditional filter devices, improves the durability of the device, avoids the inconvenience of frequent filter replacement, and improves production efficiency. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a PCB low-pressure spray coating multi-stage filtration system in an embodiment of this application;

[0028] Figure 2 This is a schematic diagram of the filter structure in an embodiment of this application;

[0029] Figure 3 This is a schematic diagram of the structure of the cylindrical filter and the flow guide in the embodiments of this application.

[0030] Figure label:

[0031] 1. Sealed container; 11. Container body; 12. Container lid;

[0032] 2. Filter; 21. Fixing part; 211. Inlet pipe; 212. Outlet pipe; 213. Interface; 22. Disassembly / assembly part; 221. Inner cavity; 222. Outer cavity; 223. Cylindrical filter screen; 2231. Limiting component; 224. Flow guide component; 2241. Protrusion; 2242. Flow channel; 225. Anti-slip ring;

[0033] 3. Sealing gasket;

[0034] 4. Pressurization device;

[0035] 5. Check valve. Detailed Implementation

[0036] Preferred embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art.

[0037] In the description of this utility model, the terms "upper", "lower", "left" and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not require that this utility model must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0038] Example 1

[0039] See Figures 1 to 3 As shown, this application provides a multi-stage filtration system for low-pressure spraying of PCBs, including a sealed barrel 1 and a filter 2. The sealed barrel 1 is connected to the filter 2. The filter 2 has two interfaces 213 that can be connected in series. When multiple filters 2 are connected in series, they are connected through the two interfaces 213 on each filter 2. The filter 2 has an inner cavity 221 and an outer cavity 222, which are connected by a cylindrical filter screen 223. The filter 2 also has an input pipe 211 and an output pipe 212. The input pipe 211 is connected to the inner cavity 221, and the output pipe 212 is connected to the outer cavity 222. The input pipe 211 and the output pipe 212 are respectively connected to the two interfaces 213. A flow guide 224 is installed in the cylindrical filter screen 223. Multiple flow channels 2242 are evenly distributed on the side wall of the flow guide 224, and a protrusion 2241 is provided between each pair of flow channels 2242.

[0040] Specifically, the sealed container 1 is used to hold the stirred ink for delivery to the filter 2. Its bottom is connected to the filter 2 via a delivery hose. Any sealed container capable of holding ink can be used, such as a commonly used plastic bucket. The two ports 213 on the filter 2 are used for ink input and output, respectively. They can be connected to the delivery hose and can be used to connect multiple filters 2 in series, thereby achieving multi-stage filtration. The inner cavity 221 and outer cavity 222 of the filter 2 are separated by a cylindrical filter screen 223. The top of the inner cavity 221 is connected to the input pipe 211, and the top of the outer cavity 222 is connected to the output pipe 212. Ink flows in from the top of the cylindrical filter screen 223, is filtered out by the cylindrical filter screen 223, and then enters the output pipe 212 connected at the top of the outer cavity 222. Both the input pipe 211 and the output pipe 212 are L-shaped conduits located at the top of the filter 2, integrally formed with the filter 2, and can be directly drilled into the top of the filter 2. The flow guide 224 is specifically a straight strip-shaped plastic part, with multiple protrusions 2241 dividing its sidewall into multiple flow channels 2242, giving its cross-sectional edge perpendicular to the axis a serrated shape. The cylindrical filter screen 223 is a metal filter screen. The flow guide 224 is vertically installed in the cylindrical filter screen 223, which can divert the ink flowing into the cylindrical filter screen 223. The cylindrical filter screen 223 covers the flow guide 224, allowing the ink to pass through the cylindrical filter screen 223 evenly from all directions. Thus, foreign particles in the ink are also dispersed, thereby preventing foreign particles from accumulating locally on the cylindrical filter screen 223 and causing blockage.

[0041] See Figure 2 As shown, the filter 2 includes a fixing part 21 and a disassembly part 22. The fixing part 21 and the disassembly part 22 are detachably connected, and a sealing gasket 3 is provided between the fixing part 21 and the disassembly part 22.

[0042] Specifically, the upper end of the fixing part 21 is sealed, and the output pipe 212 is located within the fixing part 21. The two interfaces 213 mentioned above are located on symmetrical sides of the fixing part 21. The lower end of the disassembly part 22 is sealed, and the inner cavity 221 and the outer cavity 222 are located within the disassembly part 22. The fixing part 21 can be fixedly installed on the bracket, and its bottom inner sidewall has an internal thread. The top of the disassembly part 22 has an external thread, so that the disassembly part 22 and the fixing part 21 are threadedly connected. The cylindrical filter screen 223 and the guide component 224 are placed in the disassembly part 22 and can be disassembled and replaced at any time. At the same time, the sealing gasket 3 is sleeved on the top of the disassembly part 22, located below the internal thread. After the fixing part 21 and the disassembly part 22 are connected, they can block the connection and prevent ink leakage from contaminating the working environment.

[0043] In this embodiment, the multi-stage filtration system can connect multiple fixed parts 21 in series, such as using three fixed parts 21. These parts are connected end-to-end using their two interfaces 213 and centrally fixed to a support. Identical cylindrical filter screens 223 and flow guides 224 can then be placed in three disassembly / assembly parts 22, and the three disassembly / assembly parts 22 are connected to the fixed parts 21. A sealed container 1 is then connected to any available interface 213. To ensure smooth ink flow, the bottom of the sealed container 1 should be placed on a plane higher than the interface 213. Ink can then be added for filtration. Using three identical cylindrical filter screens 223 maximizes the prevention of some foreign matter from going unfiltered, thereby improving filtration accuracy.

[0044] Example 2

[0045] See Figure 1 As shown, this embodiment is an improvement on embodiment 1, providing a PCB low-pressure spray coating multi-stage filtration system. The sealed barrel 1 is also connected to a pressurizing device 4, which is used to input air into the sealed barrel 1.

[0046] Specifically, the ink in the original sealed container 1 flows freely into the filter 2 by gravity, and the filter 2 relies on the liquid pressure of the ink itself for filtration. This results in a slow flow rate and low filtration efficiency. After setting up the pressurization device 4, the ink in the sealed container 1 can flow into the filter 2 more quickly, and the ink in the filter 2 can be filtered out quickly, thereby enhancing the filtration capacity. The sealed container 1, together with the sealing gasket 3, can prevent air leakage to ensure the effect of air pressure.

[0047] See Figure 1 As shown, the sealed barrel 1 and the filter 2 are connected by a one-way valve 5, and the flow direction of the one-way valve 5 is from the sealed barrel 1 to the filter 2.

[0048] Specifically, a delivery hose is connected to the bottom of the sealed container 1, and a one-way valve 5 is connected to the sealed container 1 and the filter 2 through the delivery hose. The pressurizing device 4 drives gas into the sealed container 1, which is squeezed above the ink and flows downward to the one-way valve 5. The one-way valve 5 controls the flow direction, allowing the ink to flow unidirectionally into the filter 2. When filtration is not in progress, closing the one-way valve 5 can prevent backflow.

[0049] See Figure 1 As shown, the one-way valve 5 is a pneumatically controlled one-way valve 5, which is connected to the pressurizing device 4.

[0050] Specifically, the pneumatically controlled check valve 5 can be a commonly used pneumatic angle seat valve. The air pressure provided by the pressurizing device 4 can control the opening and closing of the pneumatically controlled check valve 5. Specifically, when the pressurizing device 4 pressurizes the sealed container 1, the pressurizing device 4 will simultaneously deliver gas to the pneumatically controlled check valve 5 through the air supply pipe, controlling the piston in the upper cylinder of the pneumatically controlled check valve 5 to move upward, driving the piston in the lower cylinder to move upward, so that it will not block the fluid passage, thereby opening the fluid passage and allowing the ink inside to flow; when the pressurizing device 4 stops pressurizing, the upper cylinder uses an internal spring to drive the piston, thereby venting the gas delivered by the pressurizing device 4, and then simultaneously lowers the piston in the lower cylinder, blocking the fluid passage to close it, achieving the effect of preventing backflow.

[0051] Example 3

[0052] This embodiment is an improvement on embodiment 2, providing a multi-stage filtration system for low-pressure spraying of PCBs. The multi-stage filtration system is provided with multiple filters 2, each filter 2 having a cylindrical filter screen 223, and the pore sizes of the multiple cylindrical filter screens 223 are arranged in descending order.

[0053] Specifically, three filters 2 are connected in series through a fixing part 21. A cylindrical screen with different aperture is set in the disassembly part 22. The disassembly part 22 is arranged in order of aperture size, so that the ink passes through the cylindrical filter 223 with large, medium and small apertures, and the foreign particles contained therein are filtered layer by layer. Based on the three filters 2 of the same level, the ink is further purified, thereby reducing the probability of nozzle clogging or foreign objects appearing on the PCB board surface.

[0054] See Figure 1 As shown, the sealed container 1 includes a lid 12 and a body 11. The lid 12 and the body 11 are detachably connected. The air supply pipe of the pressurizing device 4 passes through the lid 12 and connects to the body 11. The body 11 is connected to the filter 2.

[0055] Specifically, the separate design of the barrel body 11 and the barrel lid 12 facilitates the addition of ink, and when the two are closed, they provide a sealed environment, which helps to ensure that the ink is not contaminated by other substances and maintains the air pressure generated by the pressurizing device 4.

[0056] See Figure 1 As shown, the outer side of the disassembly / assembly part 22 is provided with an anti-slip ring 225.

[0057] Specifically, two parallel anti-slip rings 225 are provided on the disassembly and assembly part 22. The anti-slip rings 225 are mesh or scale-like structures mechanically engraved on the outer wall of the disassembly and assembly part 22. They are integrally formed with the disassembly and assembly part 22 and surround the disassembly and assembly part 22. This helps to increase the friction between the worker's hand and the disassembly and assembly part 22, making it easier for the worker to disassemble and separate the disassembly and assembly part 22 from the fixing part 21.

[0058] See Figure 3 As shown, the top of the cylindrical filter screen 223 is provided with multiple limiting components 2231.

[0059] Specifically, four centrally symmetrical limiting members 2231 are provided on the cylindrical filter screen 223. The limiting members 2231 are square convex edges. The four limiting members 2231 are used to abut against the inner wall of the outer cavity 222 to ensure that there is a gap between the cylindrical filter screen 223 and the inner wall of the outer cavity 222. This allows the filtered ink to pass through the gap to reach the input pipe 211. Furthermore, the upper surface of the four limiting members 2231 is lower than the opening of the cylindrical filter screen 223, which ensures that after the disassembly part 22 is connected to the fixing part 21, the cylindrical filter screen 223 and the input pipe 211 are tightly connected.

[0060] Furthermore, the pressurization device 4 is an air compressor.

[0061] Specifically, the pressurizing device 4 can use a commercially available air compressor or other air source device to deliver high-pressure gas into the sealed container 1, which can drive the ink along the transmission path and speed up its passage through the cylindrical filter 223, thereby improving production efficiency.

[0062] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A multi-stage filtration system for low-pressure spraying of PCBs, comprising a sealed container (1) and a filter (2), wherein the sealed container (1) is connected to the filter (2), and the filter (2) has two interfaces (213) that can be connected in series, wherein when multiple filters (2) are connected in series, they are connected through the two interfaces (213) on each filter (2), characterized in that: The filter (2) has an inner cavity (221) and an outer cavity (222), which are connected by a cylindrical filter screen (223). The filter (2) also has an input pipe (211) and an output pipe (212). The input pipe (211) is connected to the inner cavity (221), and the output pipe (212) is connected to the outer cavity (222). The input pipe (211) and the output pipe (212) are respectively connected to two interfaces (213). A flow guide (224) is installed in the cylindrical filter screen (223). Multiple flow channels (2242) are evenly distributed on the side wall of the flow guide (224), and a protrusion (2241) is provided between each pair of flow channels (2242).

2. The PCB low-pressure spray coating multi-stage filtration system according to claim 1, characterized in that: The filter (2) includes a fixing part (21) and a disassembly part (22). The fixing part (21) and the disassembly part (22) are detachably connected, and a sealing gasket (3) is provided between the fixing part (21) and the disassembly part (22).

3. The PCB low-pressure spray coating multi-stage filtration system according to claim 1, characterized in that: The sealed container (1) is also connected to a pressurizing device (4), which is used to input air into the sealed container (1).

4. The PCB low-pressure spray coating multi-stage filtration system according to claim 3, characterized in that: The sealed container (1) and the filter (2) are connected by a one-way valve (5), and the flow direction of the one-way valve (5) is from the sealed container (1) into the filter (2).

5. The PCB low-pressure spray coating multi-stage filtration system according to claim 4, characterized in that: The one-way valve (5) is a pneumatically controlled one-way valve (5), and the pneumatically controlled one-way valve (5) is connected to the pressurizing device (4).

6. The PCB low-pressure spray coating multi-stage filtration system according to claim 1, characterized in that: The multi-stage filtration system is provided with multiple filters (2), each of which is provided with a cylindrical filter screen (223), and the pore sizes of the multiple cylindrical filter screens (223) are arranged in descending order.

7. The PCB low-pressure spray coating multi-stage filtration system according to claim 3, characterized in that: The sealed container (1) includes a lid (12) and a body (11). The lid (12) and the body (11) are detachably connected. The air supply pipe of the pressurizing device (4) passes through the lid (12) and connects to the body (11). The body (11) connects to the filter (2).

8. The PCB low-pressure spray coating multi-stage filtration system according to claim 2, characterized in that: The outer side of the disassembly / assembly part (22) is provided with an anti-slip ring (225).

9. The PCB low-pressure spray coating multi-stage filtration system according to claim 1, characterized in that: The top of the cylindrical filter screen (223) is provided with multiple limiting members (2231).

10. The PCB low-pressure spray coating multi-stage filtration system according to claim 3, characterized in that: The pressurizing device (4) is an air compressor.

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