Automatic cleaning device and solder paste printing machine applying same

Abstract

The utility model relates to the technical field of surface mounting processes, in particular to an automatic cleaning device and a solder paste printing machine applying the same. The automatic cleaning device is installed at the position of a feeding port of the solder paste printing machine and comprises an air distribution pipe, a draught fan, an air inlet pipe and an electromagnetic valve, the air distribution pipe extends in the width direction of a circuit board, and a plurality of air holes are formed in the side, facing the circuit board, of the air distribution pipe; the fan is communicated with the air distribution pipe through an air inlet pipe and is used for providing airflow required by air blowing; the electromagnetic valve is installed between the air distribution pipe and the air inlet pipe, and the electromagnetic valve and a switching power supply of the solder paste printing machine feeding mechanism are in interlocking control. When the material mechanism of the solder paste printing machine is started, the electromagnetic valve of the automatic cleaning device is automatically opened, and airflow generated by the fan is uniformly blown to the surface of a circuit board through the air holes in the air distribution pipe to blow away foreign matters such as broken filaments; and when the feeding mechanism stops, the electromagnetic valve is automatically closed, and the blowing action is automatically finished, so that the automatic cleaning function of the circuit board is realized.

Description

Technical Field

[0001] The present application relates to the field of surface mounting technology, and in particular to an automatic cleaning device and a solder paste printer using the same. Background Art

[0002] In the field of electronics, SMT refers to surface mount technology. This is an extremely popular, stable and mature process in the electronic assembly industry. It is mainly used to mount pinless or short-lead surface mount components (abbreviated as SMC / SMD, called chip components in Chinese) on the surface of printed circuit boards or other substrates, and then solder and assemble them through reflow soldering, wave soldering and other methods. SMT technology originated in the 1960s and gradually developed with the emergence of miniaturized electronic devices.

[0003] SMT technology usually consists of the following steps: printing solder paste, parts placement, welding fixation, inspection and rework, etc. Among them, the role of printing solder paste is crucial, which directly affects the subsequent component mounting quality and welding reliability. In the prior art, during the solder paste printing process, the surface of the circuit board substrate will inevitably bring in some foreign matter such as silk wool. If it is not effectively cleaned, it will directly affect the quality of subsequent solder paste printing and component mounting, resulting in an increase in the defective rate. The traditional method relies on manual use of equipment such as air guns to blow the surface of the circuit board, which is not only inefficient, but also difficult to ensure the thoroughness of cleaning, while increasing the cost of labor. Summary of the invention

[0004] In view of the deficiencies of the above-mentioned prior art, the present application provides an automatic cleaning device and a solder paste printer using the same, specifically a device for automatically cleaning the surface of a circuit board substrate during the solder paste printing process of the SMT process, aiming to solve the problem of foreign matter such as lint on the surface of the circuit board substrate affecting the product yield.

[0005] In the first aspect, the present application provides an automatic cleaning device, which is applied to the solder paste printing process in the SMT process. The automatic cleaning device is installed at the feed port of the solder paste printer, and includes: an air distribution duct, a fan, an air inlet duct and a solenoid valve. The air distribution duct extends along the width direction of the circuit board, and a plurality of air holes are provided on the side of the air distribution duct facing the circuit board; the fan is connected to the air distribution duct through the air inlet duct to provide the airflow required for blowing; the solenoid valve is installed between the air distribution duct and the air inlet duct, and the solenoid valve is interlocked with the switch power supply of the feeding mechanism of the solder paste printer.

[0006] In order to ensure stability and durability during long-term use, the air distribution duct is made of aluminum alloy material, and the extension direction of the air distribution duct is arranged perpendicular to the feeding direction of the circuit board.

[0007] In order to improve the cleaning effect and uniformity, the plurality of air holes are evenly spaced along the length direction of the air distribution pipe, and the cross-sectional size of the air holes is between 0.5-2.5 mm.

[0008] In order to increase the blowing area, the air holes opened on the air distribution pipe are of a conical structure, and the cross-sectional size of the air holes gradually increases along the air outlet direction.

[0009] In order to avoid oil impurities being introduced into the purge air flow, an oil-gas separator is provided at the front end of the air distribution pipe.

[0010] In order to effectively separate foreign matter such as hair in the airflow, multiple layers of filter screens are arranged inside the oil-gas separator, at least one layer of which is a stainless steel woven screen.

[0011] In order to facilitate the adjustment of the installation position of the automatic cleaning device, the automatic cleaning device is fixed to the feed port position of the solder paste printer through an adjustable bracket, and the installation position of the automatic cleaning device is adjusted through the adjustable bracket.

[0012] In order to further optimize the cleaning effect, the automatic cleaning device is also integrated with an electrostatic adsorption mechanism.

[0013] In order to ensure that the blowing action can be accurately controlled when the feeding mechanism starts and stops, the solenoid valve is connected to the switching power supply of the feeding mechanism of the solder paste printer through an electrical signal, its response time does not exceed 50ms, and it has a fault self-diagnosis function.

[0014] In a second aspect, the present application provides a solder paste printer, which includes the automatic cleaning device of the first aspect.

[0015] The beneficial effects of this application are:

[0016] 1. Automated cleaning: The feeding mechanism of the solder paste printer is controlled by a solenoid valve, which can automatically start the air blowing and cleaning while the circuit board is feeding, and automatically shut down the cleaning device after the feeding is completed, reducing dependence on manual labor and improving production efficiency.

[0017] 2. Good cleaning effect: Through the automated and uniform blowing, the circuit board surface is ensured to be thoroughly cleaned to meet product production requirements.

[0018] 3. Simple structure: The device has a compact structure and is easy to install and maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 According to some embodiments of the present application, a schematic structural diagram of an automatic cleaning device is shown;

[0020] Figure 2According to some embodiments of the present application, a schematic structural diagram of an air distribution duct is shown. DETAILED DESCRIPTION

[0021] The following is a more detailed description of the technical features and advantages of the present application in conjunction with the accompanying drawings, so that the advantages and features of the present application can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0022] It should be noted that, in the description of the present application, terms such as "up", "down", "left", "right", "inside", and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0023] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the importance of the technical features shown.

[0024] In addition, it should be noted that in the description of this application, 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 direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] This embodiment provides an automatic cleaning device for the solder paste printing process of the SMT process, and its structure is as follows: Figure 1-Figure 2 The automatic cleaning device is installed at the feed port of the solder paste printer to automatically remove foreign matter such as hair on the surface of the circuit board before it enters the solder paste printer. Its main components include:

[0026] Air distribution pipe 1: In order to achieve comprehensive blowing of the circuit board, the length direction of the air distribution pipe 1 can be extended along the width direction of the circuit board, and its extension length can be slightly greater than or equal to the width of the circuit board, and the length direction of the air distribution pipe 1 is perpendicular to the feeding direction of the circuit board. A plurality of air holes 101 are evenly opened along the length direction of the air distribution pipe 1 on one side facing the circuit board, so as to evenly blow air to the surface of the circuit board;

[0027] Fan 5: connected to the air distribution pipe 1 through the air inlet pipe 2 to provide the air flow required for blowing;

[0028] Air inlet pipe 2: used to connect the air distribution pipe 1 and the fan 5, and used to introduce airflow into the air distribution pipe 1;

[0029] Solenoid valve 3: installed between the air inlet duct 2 and the air distribution duct 1, its control end is interlocked with the switch power supply of the feeding mechanism of the solder paste printer to realize the function of automatically opening the water seal when the feeding mechanism starts and automatically closing it when it stops.

[0030] The working principle of the automatic cleaning device of this embodiment is as follows: when the feeding mechanism of the solder paste printer is started, the solenoid valve 3 is automatically opened, and the airflow generated by the fan 5 is evenly blown to the surface of the circuit board through the air holes 101 on the air distribution duct 1 to blow away foreign matter such as hair; when the feeding mechanism stops, the solenoid valve 3 is automatically closed and the blowing action ends automatically.

[0031] In this embodiment, the air distribution pipe 1 can be made of corrosion-resistant and wear-resistant materials such as stainless steel and aluminum alloy to ensure its corrosion resistance and stability in long-term use. In order to reduce weight, this embodiment can be made of aluminum alloy. A plurality of air holes 6 are provided on the air distribution pipe 1 at equal intervals along the length direction. The shape of the air holes 6 can be circular, square, diamond or other shapes. In order to improve the blowing effect, the air holes 6 of this embodiment are tapered air holes, and their cross-sectional dimensions gradually increase along the air outlet direction. The design of the tapered air holes is intended to increase the blowing area and improve the cleaning effect.

[0032] The fan 5 can be a centrifugal fan or an axial flow fan, and its power range can be selected according to the cleaning requirements of circuit boards of different sizes and types. The fan 5 can be fixedly connected to the air inlet pipe 2 by a flange connection to ensure the stability and sealing of the airflow.

[0033] The solenoid valve 3 is installed between the air inlet pipe 2 and the air distribution pipe 1. The control end of the solenoid valve 5 is connected to the switch power supply of the solder paste printer feed mechanism through an electrical signal. When the feed mechanism is started, the solenoid valve 3 automatically receives the electrical signal and opens, allowing the airflow to blow to the surface of the circuit board through the air distribution pipe 1; when the feed mechanism stops, the solenoid valve 3 automatically closes and cuts off the airflow supply. The response time of the solenoid valve 3 has been optimized to ensure that the blowing action can be started in a very short time after the feed mechanism is started. The response time does not exceed 50 milliseconds to meet the needs of fast response.

[0034] In order to prevent the oil and dirt brought into the air pipe from falling onto the surface of the circuit board, an oil-gas separator 4 can be installed at the front end of the air distribution pipe 1 to filter the oil and dirt impurities in the intake air before blowing toward the circuit board. The oil-gas separator 4 is provided with multiple layers of filter screens inside, including at least one layer of stainless steel woven screens, which is used to efficiently separate foreign matter such as hair from the air flow. When the air flow carries foreign matter through the oil-gas separator 4, the foreign matter will settle in the filter screen, and the cleaned air flow will be blown out through the air distribution pipe 1.

[0035] In order to further improve the cleaning effect, an electrostatic adsorption mechanism can be added to the cleaning device to adsorb foreign matter such as silk wool to further optimize the cleaning effect. The above-mentioned electrostatic adsorption mechanism can be an electrostatic brush, an electrostatic roller or an electrostatic adsorption plate. The electrostatic brush or electrostatic roller can be detachably installed in parallel with the air distribution pipe 1. After the circuit board is initially cleaned by blowing, the electrostatic brush and the electrostatic roller will adsorb the raised silk wool impurities to further increase the cleaning effect. The electrostatic adsorption plate can be designed and installed above the air distribution pipe 1. The surface of the electrostatic adsorption plate has static electricity, which can adsorb tiny impurities raised during the movement of the circuit board. Other electrostatic adsorption mechanisms can also be electrostatic belts or electrostatic cloths, which can be wrapped around the air distribution pipe 1 (avoiding the air holes 101). Compared with other electrostatic adsorption devices, electrostatic belts or electrostatic cloths can be cut and installed according to specific structures and needs, and the cost is lower.

[0036] In actual application, the automatic cleaning device is installed at the entrance of the solder paste printer. The device can be fixed at an appropriate height and angle by an adjustable bracket to ensure that the air holes 101 on the air distribution duct 1 can fully cover and effectively clean the surface of the circuit board. Before the circuit board enters the solder paste printer, the feeding mechanism starts and triggers the solenoid valve 3 to open. The airflow generated by the fan 2 blows evenly toward the surface of the circuit board through the air holes 101 on the air distribution duct 1, blowing away foreign matter such as hair. After the circuit board completely passes through the cleaning area, the feeding mechanism stops and triggers the solenoid valve 3 to close, and the blowing action ends. The entire process realizes the automatic cleaning of the circuit board surface without manual intervention, greatly improving production efficiency and cleaning effect.

[0037] It can be seen from the description of this embodiment that the automatic cleaning device provided by the utility model has the advantages of simple structure, convenient installation, good cleaning effect and high degree of automation. It can effectively solve the problem of product defect rate caused by foreign matter such as hair on the surface of the circuit board substrate in the SMT process, and improve product quality and production efficiency.

[0038] In the description of this specification, the description with reference to the terms "some embodiments", "some examples", "exemplarily", "example", "preferably", or "further" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0039] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An automatic cleaning device, applied to the solder paste printing process in the SMT process, characterized in that: The automatic cleaning device is installed at the feed port of the solder paste printer, and includes: an air distribution duct, a fan, an air inlet duct and a solenoid valve. The air distribution duct extends along the width direction of the circuit board, and a plurality of air holes are provided on the side of the air distribution duct facing the circuit board; the fan is connected to the air distribution duct through the air inlet duct to provide the airflow required for blowing; the solenoid valve is installed between the air distribution duct and the air inlet duct, and the solenoid valve is interlocked with the switch power supply of the feeding mechanism of the solder paste printer.

2. The automatic cleaning device according to claim 1, characterized in that: The air distribution duct is made of aluminum alloy material, and the extension direction of the air distribution duct is arranged perpendicular to the feeding direction of the circuit board.

3. The automatic cleaning device according to claim 1, characterized in that: The plurality of air holes are evenly spaced apart along the length direction of the air distribution duct, and the cross-sectional size of the air holes is between 0.5-2.5 mm.

4. The automatic cleaning device according to claim 3, characterized in that: The air holes opened on the air distribution pipe are of a conical structure, and the cross-sectional size of the air holes gradually increases along the air outlet direction.

5. The automatic cleaning device according to claim 1, characterized in that: An oil-gas separator is arranged at the front end of the air distribution pipe.

6. The automatic cleaning device according to claim 5, characterized in that: Multiple layers of filter screens are arranged inside the oil-gas separator, at least one layer of which is a stainless steel woven screen.

7. The automatic cleaning device according to claim 1, characterized in that: The automatic cleaning device is fixed to the feed port position of the solder paste printer through an adjustable bracket, and the installation position of the automatic cleaning device is adjusted through the adjustable bracket.

8. The automatic cleaning device according to claim 1, characterized in that: The automatic cleaning device is also integrated with an electrostatic adsorption mechanism.

9. The automatic cleaning device according to claim 1, characterized in that: The solenoid valve is connected to the switch power supply of the feeding mechanism of the solder paste printer through an electrical signal, the response time thereof does not exceed 50ms, and the solenoid valve has a fault self-diagnosis function.

10. A solder paste printer, characterized in that: The invention comprises the automatic cleaning device as described in any one of claims 1 to 9.

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