A printed circuit board screen cleaning device

Abstract

The utility model discloses a kind of printed circuit board steel net cleaning devices, belong to printed circuit board production equipment field, including turnover mechanism, dry ice sprayer, turnover mechanism includes driving part, vertical plate, driving shaft, driven shaft, first gear, second gear, two expansion sleeves, two clamping jaws, driving shaft is installed on the output shaft of driving part, first gear is installed in the other end of driving shaft, second gear is installed in one end of driven shaft and is engaged with first gear, two expansion sleeves are respectively arranged in the both ends of driven shaft, each clamping jaw is arranged on one expansion sleeve, the clamping region for clamping steel net is formed between two clamping jaws, dry ice sprayer includes nozzle, nozzle is towards clamping region, driving part drives driving shaft rotation, and driven shaft and clamping jaw, steel net are driven to overturn, nozzle sprays dry ice particle and carries out cleaning to tin paste on the front and back of steel net. While the application enhances cleaning effect, avoids that liquid cleaning agent penetrates into micropore and remains, is not easy to cause secondary pollution.

Description

Technical Field

[0001] This utility model relates to the field of printed circuit board production equipment, and in particular to a stencil cleaning device for printed circuit boards. Background Technology

[0002] In the SMT soldering process of printed circuit boards, solder paste is usually printed onto the pads of the circuit board using a solder paste printer. The solder paste printer generally consists of a plate mounting, solder paste application, and imprinting output circuit board mechanism. Its working principle is as follows: first, the circuit board to be printed is fixed on the printing positioning table, and then the left and right squeegees of the printer print the solder paste through the stencil onto the corresponding pads. The printed circuit board (PCB) with uniform imprinting is then fed into the pick and place machine through the transfer table for automatic placement of electrical components.

[0003] A commonly used component in the printing process is the stencil. The mesh openings on the stencil correspond to the solder pads on the circuit board. Whether the stencil is clean and whether the mesh openings are clogged are important factors affecting the printing effect. If the stencil mesh openings are clogged, solder paste will not be printed on the corresponding solder pads, affecting the subsequent placement process.

[0004] Existing steel mesh cleaning devices generally only clean one side of the steel mesh, and cannot clean the steel mesh in all directions, resulting in cleaning dead corners, which affects the cleaning effect. Moreover, liquid cleaning agents can seep into the micropores and leave residues, which can easily cause secondary pollution. Utility Model Content

[0005] In order to overcome the shortcomings of the existing technology, the purpose of this utility model is to provide a stencil cleaning device for printed circuit boards. The stencil is flipped by a flipping mechanism and the front and back of the stencil are cleaned by a dry ice sprayer, which enhances the cleaning effect. At the same time, the heat absorption of the sublimation of dry ice causes the solder paste to become brittle and fall off, avoiding the seepage of liquid cleaning agent into the micropores and preventing secondary pollution.

[0006] The objective of this utility model is achieved through the following technical solution:

[0007] A stencil cleaning device for printed circuit boards includes a flipping mechanism and a dry ice blasting machine. The flipping mechanism includes a driving component, a vertical plate, a drive shaft, a driven shaft, a first gear, a second gear, two expansion sleeves, and two grippers. The drive shaft and the driven shaft are arranged parallel to each other on the vertical plate. The drive shaft is mounted on the output shaft of the driving component. The first gear is mounted on the other end of the drive shaft, and the second gear is mounted on one end of the driven shaft and meshes with the first gear. The two expansion sleeves are respectively disposed at both ends of the driven shaft. Each gripper is disposed on one expansion sleeve, and a clamping area for clamping the stencil is formed between the two grippers. The dry ice blasting machine includes a nozzle facing the clamping area. The grippers are clamped by rotating the expansion sleeves. The driving component drives the drive shaft to rotate, thereby flipping the driven shaft, grippers, and stencil. The nozzle sprays dry ice particles to clean the solder paste on both sides of the stencil.

[0008] Furthermore, the driving component includes a driving cylinder and a connecting rod. The driving cylinder is installed on one side of the upright plate. One end of the connecting rod is installed on the output shaft of the driving cylinder, and the other end is installed on one end of the drive shaft. The driving cylinder converts linear motion into rotational motion through the connecting rod, thereby driving the drive shaft to rotate.

[0009] Furthermore, the diameter of the first gear is larger than the diameter of the second gear, and the transmission ratio between the first gear and the second gear is 2:1.

[0010] Furthermore, the dry ice blasting machine also includes a dry ice storage chamber, a stirring shaft, a high-pressure air source system, and a blasting channel. The dry ice storage chamber contains dry ice, and the stirring shaft is rotatably disposed within the dry ice storage chamber. One end of the blasting channel is connected to the dry ice storage chamber and the high-pressure air source system, and the other end is connected to the nozzle. The high-pressure air source system uses compressed air to transport dry ice to the blasting channel.

[0011] Compared to existing technologies, this utility model's printed circuit board stencil cleaning device includes a flipping mechanism and a dry ice blasting machine. The flipping mechanism includes a driving component, a vertical plate, a drive shaft, a driven shaft, a first gear, a second gear, two expansion sleeves, and two grippers. The drive shaft and driven shaft are arranged parallel to each other on the vertical plate. The drive shaft is mounted on the output shaft of the driving component. The first gear is mounted on the other end of the drive shaft, and the second gear is mounted on one end of the driven shaft and meshes with the first gear. The two expansion sleeves are respectively located at both ends of the driven shaft, and each gripper is mounted on one expansion sleeve. A gripping area for holding the stencil is formed between the two grippers. The dry ice blasting machine includes a nozzle facing the gripping area. The grippers are clamped by rotating the expansion sleeves. The driving component drives the drive shaft to rotate, which in turn drives the driven shaft, grippers, and stencil to flip. The nozzle sprays dry ice particles to clean the solder paste on both sides of the stencil.

[0012] In use, this application first clamps the stencil using a tension sleeve and grippers. Then, a drive unit rotates the drive shaft, causing the driven shaft, grippers, and stencil to flip. Simultaneously, a high-pressure air source system uses compressed air to deliver dry ice to the spray channel. The nozzles spray dry ice particles to clean the solder paste on both sides of the stencil. This application uses a flipping mechanism to flip the stencil while simultaneously cleaning both sides with a dry ice sprayer, enhancing the cleaning effect. Furthermore, the sublimation and heat absorption of the dry ice cause the solder paste to become brittle and fall off, preventing liquid cleaning agents from seeping into the micropores and leaving residue, thus minimizing the risk of secondary contamination. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the printed circuit board stencil cleaning device of this utility model;

[0014] Figure 2 for Figure 1 A schematic diagram of the flipping mechanism of a printed circuit board stencil cleaning device;

[0015] Figure 3 for Figure 1 Another schematic diagram of the flipping mechanism of the printed circuit board stencil cleaning device;

[0016] Figure 4 for Figure 1 A schematic diagram of the dry ice jet machine in a printed circuit board stencil cleaning device;

[0017] Figure 5 for Figure 1 Another schematic diagram of the dry ice jet machine for cleaning printed circuit board stencils.

[0018] In the diagram: 10. Tilting mechanism; 11. Driving component; 111. Driving cylinder; 112. Connecting rod; 12. Vertical plate; 13. Drive shaft; 14. Driven shaft; 15. First gear; 16. Second gear; 17. Expansion sleeve; 18. Gripper; 20. Dry ice jetting machine; 21. Dry ice storage chamber; 211. Dry ice conveying channel; 22. Stirring shaft; 23. High-pressure air source system; 231. Compressed air conveying channel; 24. Jetting channel; 25. Nozzle. Detailed Implementation

[0019] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0020] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Figures 1-5 The present invention relates to a stencil cleaning device for printed circuit boards, comprising a flipping mechanism 10 and a dry ice jetting machine 20.

[0023] In this embodiment:

[0024] The flipping mechanism 10 includes a driving component 11, a vertical plate 12, a drive shaft 13, a driven shaft 14, a first gear 15, a second gear 16, two expansion sleeves 17, and two grippers 18.

[0025] The drive shaft 13 and the driven shaft 14 are arranged in parallel on the vertical plate 12, and the drive shaft 13 is mounted on the output shaft of the drive component 11.

[0026] The first gear 15 is mounted on the other end of the drive shaft 13, and the second gear 16 is mounted on one end of the driven shaft 14 and meshes with the first gear 15. In this embodiment, the diameter of the first gear 15 is larger than the diameter of the second gear 16, and the transmission ratio between the first gear 15 and the second gear 16 is 2:1.

[0027] Two expansion sleeves 17 are respectively disposed at both ends of the driven shaft 14, and each jaw 18 is disposed on one expansion sleeve 17. A clamping area for holding the steel mesh is formed between the two jaws 18. The jaws 18 are clamped by rotating the expansion sleeves 17. Specifically, the expansion sleeve 17 is a keyless connection device, typically consisting of an open elastic sleeve and one or more fastening bolts. When the fastening bolts of the expansion sleeve 17 are tightened, the elastic sleeve expands radially, thereby tightly gripping the mating shaft and jaws 18. This connection method can provide a large clamping force, ensuring a reliable connection between the jaws 18 and the shaft, and is capable of transmitting torque and withstanding a certain axial force.

[0028] The driving component 11 includes a driving cylinder 111 and a connecting rod 112. The driving cylinder 111 is installed on one side of the upright plate 12. One end of the connecting rod 112 is installed on the output shaft of the driving cylinder 111, and the other end is installed on one end of the drive shaft 13. The driving cylinder 111 converts linear motion into rotational motion through the connecting rod 112, thereby driving the drive shaft 13 to rotate and causing the driven shaft 14, gripper 18, and steel mesh to flip, so that the dry ice blasting machine 20 can thoroughly and effectively clean the front and back of the steel mesh.

[0029] The dry ice jetting machine 20 includes a dry ice storage chamber 21, a stirring shaft 22, a high-pressure air source system 23, a jetting channel 24, and a nozzle 25.

[0030] The dry ice storage chamber 21 contains dry ice. A stirring shaft 22 is rotatably mounted inside the dry ice storage chamber 21. A nozzle 25 faces the clamping area. One end of the injection channel 24 is connected to the dry ice storage chamber 21 and the high-pressure air source system 23, and the other end is connected to the nozzle 25. Specifically, a dry ice delivery channel 211 is connected to the outlet of the dry ice storage chamber 21, and a compressed air delivery channel 231 is connected to the outlet of the high-pressure air source system 23. Both the dry ice delivery channel 211 and the compressed air delivery channel 231 are connected to the injection channel 24.

[0031] The high-pressure air source system 23 uses compressed air to deliver dry ice to the spray channel 24, and the nozzle 25 sprays dry ice particles to clean the solder paste on both sides of the stencil. Specifically, when the dry ice particles come into contact with the surface of the stencil, they rapidly sublimate, changing directly from a solid to a gaseous state. Within a fraction of a second, the volume of the dry ice particles expands nearly 800 times, producing a "micro-explosion" effect. This expansion force peels off the brittle and loose solder paste from the stencil surface and blows it away. At the same time, the sublimated carbon dioxide gas also carries away some residue, achieving a thorough cleaning effect without causing secondary pollution. In this embodiment, the diameter of the dry ice particles is 0.3–0.5 mm, the spray pressure is 0.5–0.8 MPa, the distance from the stencil surface is 10–15 cm, and the scanning speed along the vertical direction of the opening is 5–10 cm / s.

[0032] In use, this application first clamps the stencil using the expansion sleeve and grippers 18. Then, the drive unit 11 drives the drive shaft 13 to rotate, causing the driven shaft 14, grippers 18, and stencil to flip. Simultaneously, the high-pressure air source system 23 uses compressed air to deliver dry ice to the spray channel 24, and the nozzle 25 sprays dry ice particles to clean the solder paste on both sides of the stencil. This application uses the flipping mechanism 10 to flip the stencil, while simultaneously using the dry ice sprayer 20 to clean both sides of the stencil, enhancing the cleaning effect. Furthermore, the sublimation and heat absorption of the dry ice cause the solder paste to become brittle and fall off, preventing liquid cleaning agents from seeping into the micropores and leaving residue, thus minimizing the risk of secondary contamination.

[0033] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A stencil cleaning device for printed circuit boards, characterized in that: The system includes a tilting mechanism (10) and a dry ice jetting machine (20). The tilting mechanism (10) includes a driving member (11), a vertical plate (12), a driving shaft (13), a driven shaft (14), a first gear (15), a second gear (16), two expansion sleeves (17), and two grippers (18). The driving shaft (13) and the driven shaft (14) are arranged parallel to each other on the vertical plate (12). The driving shaft (13) is mounted on the output shaft of the driving member (11). The first gear (15) is mounted on the other end of the driving shaft (13), and the second gear (16) is mounted on one end of the driven shaft (14) and is parallel to the first gear (15). The two expansion sleeves (17) are respectively disposed at both ends of the driven shaft (14), and each of the grippers (18) is disposed on one of the expansion sleeves (17). A clamping area for clamping the stencil is formed between the two grippers (18). The dry ice blasting machine (20) includes a nozzle (25) facing the clamping area. The grippers (18) are clamped by rotating the expansion sleeves (17). The driving member (11) drives the drive shaft (13) to rotate and drives the driven shaft (14), grippers (18), and stencil to rotate. The nozzle (25) sprays dry ice particles to clean the solder paste on both sides of the stencil.

2. The printed circuit board stencil cleaning device according to claim 1, characterized in that: The driving component (11) includes a driving cylinder (111) and a connecting rod (112). The driving cylinder (111) is installed on one side of the upright plate (12). One end of the connecting rod (112) is installed on the output shaft of the driving cylinder (111), and the other end is installed on one end of the drive shaft (13). The driving cylinder (111) converts linear motion into rotational motion through the connecting rod (112), thereby driving the drive shaft (13) to rotate.

3. The printed circuit board stencil cleaning device according to claim 1, characterized in that: The diameter of the first gear (15) is larger than the diameter of the second gear (16), and the transmission ratio between the first gear (15) and the second gear (16) is 2:

1.

4. The printed circuit board stencil cleaning device according to claim 1, characterized in that: The dry ice jetting machine (20) also includes a dry ice storage chamber (21), a stirring shaft (22), a high-pressure air source system (23), and a jetting channel (24). The dry ice storage chamber (21) contains dry ice. The stirring shaft (22) is rotatably disposed in the dry ice storage chamber (21). One end of the jetting channel (24) is connected to the dry ice storage chamber (21) and the high-pressure air source system (23), and the other end is connected to the nozzle (25). The high-pressure air source system (23) uses compressed air to transport dry ice to the jetting channel (24).

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