SMT (Surface Mount Technology) device and SMT process

Abstract

The invention relates to the technical field of SMT (surface mount technology), in particular to an SMT device and process, comprising a mounting rack, a mounting frame for solder paste printing is fixedly mounted in the middle of the mounting rack, a steel mesh is arranged in the mounting frame, a sliding plate for conveying a PCB (printed circuit board) is arranged in the middle of the mounting rack, and the SMT device further comprises a scraper assembly, the tin paste smearing device is slidably mounted above the mounting frame and is used for smearing the tin paste on the steel mesh, so that the tin paste on the surface of the steel mesh is attached to the PCB; the cleaning assembly is arranged on one side of the scraper assembly and used for cleaning the scraper assembly in the solder paste printing process; the adjusting assembly comprises a sliding frame and is used for driving the scraper assembly to move up and down and left and right; wherein the scraper assembly and the cleaning assembly are both arranged on one side of the sliding frame and located above the mounting frame, the scraper assembly can be cleaned in time after the scraper assembly is smeared with solder paste for one time, solder paste residues are reduced, and the processing efficiency of solder paste printing is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of SMT patch technology, and particularly relates to an SMT patch device and a patch process. BACKGROUND

[0002] The SMT patch machine is a series of process flow machines based on the processing of the PCB printed circuit board; the tin paste smearing (usually referred to as tin paste printing) in the SMT (surface mount technology) is the most important and most basic first step in the whole SMT process. Its quality directly affects the accuracy of subsequent patching and the reliability of reflow soldering; In the tin paste printing process, the tin paste is first extruded on the steel mesh, and then the tin paste is extruded into the holes inside the steel mesh by moving the scraper on one side of the steel mesh. Usually after a certain number of tin paste printing (such as 5-10 times) or after each printing cycle, the steel mesh needs to be cleaned (wet and dry cloths (usually dipped in alcohol or special solvent) will automatically wipe the bottom surface of the steel mesh according to the set program, remove the remaining tin paste, dust or fibers, prevent the opening from being blocked and contaminated PCB), but this cleaning structure can only clean the steel mesh, and cannot clean the tin paste remaining on the surface of the scraper. Usually after a certain number of runs, manual cleaning is required, which will affect the processing efficiency of the tin paste printing. SUMMARY

[0003] Technical problems to be solved In view of the above-mentioned shortcomings of the prior art, the present application provides an SMT patch device, which can effectively solve the problem that the existing technology usually needs to clean the steel mesh after a certain number of tin paste printing or after each printing cycle, but this cleaning structure can only clean the steel mesh, and cannot clean the tin paste remaining on the surface of the scraper. Usually after a certain number of runs, manual cleaning is required, which will affect the processing efficiency of the tin paste printing.

[0004] Technical scheme To achieve the above purpose, the present application is realized by the following technical scheme: The present application provides an SMT patch device, comprising a mounting frame, a mounting frame is fixedly installed in the middle part for tin paste printing, a steel mesh is arranged in the mounting frame, a sliding plate for conveying the PCB is arranged in the middle part of the mounting frame, and the mounting frame further comprises: A scraper assembly is slidably installed above the mounting frame for smearing the tin paste on the steel mesh so that the tin paste on the surface of the steel mesh is attached to the PCB; A cleaning assembly is arranged on one side of the scraper assembly for cleaning the scraper assembly during the tin paste printing process; An adjusting assembly comprises a sliding frame for driving the scraper assembly to move up and down and left and right; The scraper assembly and the cleaning assembly are arranged on one side of the sliding frame and above the mounting frame.

[0005] Further, the sliding frame is slidingly mounted above the mounting frame, and linear motors are arranged on both sides of the sliding frame to drive the sliding frame to slide on the mounting frame.

[0006] Further, a slide rail is fixedly mounted at the middle of the sliding frame, a sliding block is slidingly mounted on the slide rail, a trapezoidal rod is fixedly mounted on the side of the sliding block away from the slide rail, the scraper assembly is fixedly mounted at the end of the trapezial rod away from the sliding block, a screw rod is rotatably mounted on the sliding frame to drive the sliding block to move up and down, and a driving motor is arranged in the sliding frame to drive the screw rod to rotate.

[0007] Further, the scraper assembly comprises a mounting plate fixedly mounted on the trapezoidal rod and a scraper plate below the mounting plate, a rotating connection shaft is rotatably mounted below the mounting plate to rotatably connect with the scraper plate, a scraper is fixedly mounted below the scraper plate, and the cleaning assembly is arranged between the scraper plate and the sliding frame.

[0008] Further, an L-shaped plate is slidingly mounted on the side of the mounting plate away from the sliding frame to adjust the rotation of the scraper on the scraper plate to the inside of the cleaning assembly.

[0009] Further, a horizontal plate is arranged on the side of the mounting plate away from the sliding frame, the horizontal plate is slidingly mounted on the L-shaped plate, a gear rack is arranged on the side of the L-shaped plate facing the sliding frame, a gear wheel is fixedly mounted on the rotating connection shaft to engage with the gear rack, an elastic member is fixedly mounted above the horizontal plate to drive the L-shaped plate to move upward, and a limiting rod is fixedly mounted above the cleaning assembly to limit the upward movement of the L-shaped plate during the upward movement of the sliding block.

[0010] Further, a limiting groove is arranged on the side of the mounting plate away from the sliding frame to guide the upward and downward movement of the gear rack, and the top of the gear rack abuts against the upper inner wall of the limiting groove.

[0011] Further, the cleaning assembly comprises a cleaning box fixedly mounted on one side of the sliding frame, a cleaning frame is arranged on the side of the cleaning box facing the scraper plate, the opening profile of the cleaning frame matches the profile of the scraper plate, a reciprocating shaft is slidingly mounted in the cleaning frame, a reciprocating driving member is arranged on one side of the cleaning frame to drive the reciprocating shaft to reciprocate, a plurality of cleaning plates are arranged on the reciprocating shaft at intervals, and the cleaning plates are used to scrape the residual solder paste on the surface of the scraper.

[0012] Further, a plurality of high-pressure nozzles are fixedly mounted on the top of the cleaning frame, the lower ends of the high-pressure nozzles respectively extend into the inside of the cleaning frame, the high-pressure nozzles are respectively arranged between the plurality of cleaning plates, and the high-pressure nozzles are used to flush the residual solder paste on the surface of the scraper.

[0013] An SMT patch process, comprising the following steps: S1, first, the PCB to be patched is placed on the conveying structure on the mounting frame, and the PCB is positioned; S2, then, the PCB to be patched is supported below the steel mesh, and the doctor blade assembly is driven to move to one side of the steel mesh, while the tin paste is extruded onto the steel mesh; S3, then, the doctor blade assembly is driven to scrape the tin paste across the steel mesh, so that the tin paste is extruded into the corresponding holes in the steel mesh; S4, finally, the adjusting assembly is driven to move the doctor blade assembly upward, so that the doctor blade assembly moves to the cleaning assembly for cleaning.

[0014] Advantages The technical scheme provided by the present application has the following advantages compared with known prior art: By arranging the cleaning assembly on the side surface of the doctor blade assembly, the doctor blade assembly can be cleaned in time after a single tin paste application, tin paste residue is reduced, the doctor blade assembly can more smoothly extrude the tin paste into the holes in the steel mesh, and the processing efficiency of tin paste printing is increased. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0016] Figure 1 is a schematic diagram of the overall structure of the present application; Figure 2 is a schematic diagram of the overall structure of the mounting frame of the present application; Figure 3 is a schematic diagram of the internal mounting structure of the sliding frame of the present application; Figure 4 is an exploded view of the doctor blade assembly of the present application; Figure 5 is a partial sectional view of the doctor blade assembly of the present application; Figure 6 is a schematic diagram of the overall structure of the cleaning assembly of the present application; Figure 7 is a schematic diagram of the state change of the doctor blade plate of the present application; Figure 8 is a schematic diagram of the internal structure of the cleaning frame of the present application.

[0017] The reference numbers in the drawings represent respectively: 1. Mounting bracket; 11. Sliding plate; 2. Mounting frame; 21. Steel mesh; 22. Sliding bracket; 23. Slide rail; 24. Screw; 241. Drive motor; 25. Slider; 26. Trapezoidal rod; 3. Scraper assembly; 301. Mounting groove; 31. Scraper plate; 311. Scraper; 32. Rotary connecting shaft; 321. Gear; 33. Horizontal plate; 34. L-shaped plate; 341. Tooth row; 35. Elastic element; 4. Cleaning components; 41. Limiting rod; 42. Reciprocating drive component; 43. Cleaning frame; 431. High-pressure nozzle; 432. Cleaning plate; 433. Reciprocating shaft. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0019] The present invention will be further described below with reference to embodiments.

[0020] Therefore, this embodiment of the invention provides an SMT placement device, the purpose of which is at least to clean the squeegee assembly 3 in a timely manner after the squeegee assembly 3 has applied solder paste once, by providing a cleaning component 4 on the side of the squeegee assembly 3, thereby reducing solder paste residue and making it easier for the squeegee assembly 3 to squeeze the solder paste into the holes on the stencil 21.

[0021] Example: An SMT placement apparatus, such as Figure 1 - Figure 8 As shown, the PCB includes a mounting frame 1, a mounting frame 2 for solder paste printing fixedly mounted in the middle of the mounting frame 1, a stencil 21 inside the mounting frame 2, and a sliding plate 11 for conveying the PCB board in the middle of the mounting frame 1. It also includes: The scraper assembly 3 is slidably mounted above the mounting frame 2 and is used to apply solder paste to the stencil 21 so that the solder paste on the surface of the stencil 21 adheres to the PCB board. Cleaning component 4 is located on one side of squeegee component 3 and is used to clean squeegee component 3 during solder paste printing; The adjustment component includes a sliding frame 22, which is used to drive the scraper assembly 3 to move up and down and left and right; The scraper assembly 3 and the cleaning assembly 4 are both located on one side of the sliding frame 22 and above the mounting frame 2.

[0022] In the present application, by arranging the cleaning assembly 4 on one side of the scraper assembly 3, after the tin paste coating of the scraper assembly 3 is completed, the scraper assembly 3 can be moved to the cleaning assembly 4 by adjusting the assembly, so as to clean the tin paste remaining on the surface of the scraper assembly 3, avoid the excess tin paste adhering to the scraper assembly 3, and improve the coating efficiency of the tin paste by the scraper assembly 3.

[0023] Further, the sliding frame 22 is slidingly installed above the mounting frame 2, and linear motors are arranged on the two sides of the sliding frame 22 for driving the sliding frame 22 to slide on the mounting frame 2.

[0024] Wherein, by arranging the linear motors on the two sides of the sliding frame 22, when the scraper assembly 3 on the sliding frame 22 coats the tin paste, the linear motors can be driven to drive the scraper assembly 3 and the sliding frame 22 to slide stably above the steel mesh 21.

[0025] Further, as shown in Figure 3 and Figure 4 , the middle part of the sliding frame 22 is fixedly installed with a sliding rail 23, the sliding rail 23 is slidingly installed with a sliding block 25, the side of the sliding block 25 away from the sliding rail 23 is fixedly installed with a trapezoidal rod 26, the scraper assembly 3 is fixedly installed at the end of the trapezoidal rod 26 away from the sliding block 25, the sliding frame 22 is rotatably installed with a screw rod 24 for driving the sliding block 25 to move up and down, the sliding frame 22 is provided with a partition plate, the driving motor 241 is fixedly installed on the partition plate, and the top of the sliding rail 23 is fixedly connected with the partition plate.

[0026] Wherein, by fixing the sliding rail 23 on the sliding frame 22, the sliding block 25 can be guided to move up and down, and by rotatably installing the screw rod 24, when the up-down position of the scraper assembly 3 needs to be adjusted, the screw rod 24 can be driven to rotate by the driving motor 241, so that the sliding block 25 moves up and down along the sliding rail 23, and the scraper assembly 3 moves up and down stably. Further, as shown in Figure 4 and Figure 5 , the scraper assembly 3 comprises a mounting plate fixedly installed on the trapezoidal rod 26 and a scraper plate 31 below the mounting plate, a rotating connection shaft 32 for rotatingly connecting with the scraper plate 31 is rotatably installed below the mounting plate, a scraper 311 is fixedly installed below the scraper plate 31, and the cleaning assembly 4 is located between the scraper plate 31 and the sliding frame 22; an L-shaped plate 34 for adjusting the scraper 311 on the scraper plate 31 to rotate into the cleaning assembly 4 is slidingly installed on the side of the mounting plate away from the sliding frame 22.

[0027] Wherein, by rotating the installation plate 31 below, and fixedly installing the scraper 311 on the scraper plate 31, when the scraper 311 needs to be cleaned, by pressing the L-shaped plate 34, the scraper plate 31 can be rotated around the rotating connection shaft 32, and the scraper 311 is rotated to the inside of the cleaning assembly 4 for cleaning.

[0028] It should be noted that the installation groove 301 is arranged on the installation plate, and when the installation plate is fixedly installed on one side of the trapezoidal rod 26, the installation groove 301 is clamped on the outer side of one end of the trapezoidal rod 26.

[0029] Further, as shown in Figure 4 and Figure 5 , the installation plate is provided with a transverse plate 33 away from one side of the sliding frame 22, the L-shaped plate 34 is slidably installed on the transverse plate 33, the L-shaped plate 34 is provided with a gear row 341 on the side facing the sliding frame 22, the rotating connection shaft 32 is fixedly installed with a gear 321 for engaging with the gear row 341, the transverse plate 33 is fixedly installed with an elastic member 35 above for driving the L-shaped plate 34 to move upward, and the cleaning assembly 4 is fixedly installed with a limiting rod 41 above for limiting the upward movement of the L-shaped plate 34 during the upward movement of the sliding block 25; the installation plate is provided with a limiting groove for guiding the upward and downward movement of the gear row 341, and the top of the gear row 341 abuts against the upper inner wall of the limiting groove.

[0030] Wherein, by arranging the gear row 341 on one side of the L-shaped plate 34, and coaxially fixedly installing the gear 321 on the rotating connection shaft 32, in the normal state, the top of the gear row 341 abuts against the upper inner wall of the limiting groove under the action of the elastic member 35, at this time the scraper plate 31 is in a vertical state, when the scraper 311 on the scraper plate 31 needs to be cleaned, by moving the installation plate and the scraper plate 31 upward, the L-shaped plate 34 can be driven to move upward, when the top of the L-shaped plate 34 abuts against the limiting rod 41, with the continuous upward movement of the installation plate and the scraper plate 31, the gear row 341 on the side of the L-shaped plate 34 will drive the gear 321 to rotate, thereby driving the scraper plate 31 to rotate, so that the scraper plate 31 is adjusted to a horizontal state, facilitating the cleaning of the surface of the scraper 311 by the cleaning assembly 4.

[0031] Further, as shown in Figure 7 and Figure 8As shown, the cleaning assembly 4 includes a cleaning box fixedly installed on one side of the sliding frame 22, and the cleaning box is provided with a cleaning frame 43 on the side facing the squeegee plate 31. The opening profile of the cleaning frame 43 matches the profile of the squeegee plate 31. When the squeegee plate 31 is turned to the side of the cleaning frame 43, the bottom of the squeegee plate 31 is attached to the side of the cleaning frame 43. A reciprocating shaft 433 is slidably installed in the interior of the cleaning frame 43. A reciprocating drive 42 is provided on one side of the cleaning frame 43 to drive the reciprocating shaft 433 to reciprocate. A plurality of cleaning plates 432 are provided on the reciprocating shaft 433 at intervals. The cleaning plates 432 are used to scrape the tin paste remaining on the surface of the squeegee 311. A plurality of high-pressure nozzles 431 are fixedly installed on the top of the cleaning frame 43. The lower ends of the plurality of high-pressure nozzles 431 extend into the interior of the cleaning frame 43 (the positions of the high-pressure nozzles 431 do not extend between the cleaning plates 432 and do not hinder the reciprocating movement of the cleaning plates 432). The plurality of high-pressure nozzles 431 are respectively located between the plurality of cleaning plates 432. The high-pressure nozzles 431 are used to flush the tin paste remaining on the surface of the squeegee 311. The other ends of the plurality of high-pressure nozzles 431 are in communication with an external high-pressure flushing device.

[0032] By providing the cleaning frame 43 on one side of the cleaning box and reciprocally installing the reciprocating shaft 433 in the interior of the cleaning frame 43, when the squeegee 311 is turned to the interior of the cleaning frame 43, the reciprocating shaft 433 is driven by the reciprocating drive 42 to reciprocate, so that the plurality of cleaning plates 432 on the reciprocating shaft 433 reciprocate on the squeegee 311 at different positions respectively, and the tin paste is scraped at different positions of the squeegee 311 respectively. After the initial scraping, the surface of the squeegee 311 is flushed by the high-pressure nozzles 431, so that the tin paste remaining on the squeegee 311 can be thoroughly cleaned.

[0033] It should be noted that a dust collection device is provided in the interior of the cleaning box to collect the tin paste cleaned and the cleaning liquid sprayed. The device is a common device in the prior art that collects by negative pressure adsorption principle, so it will not be described here.

[0034] An SMT patch process includes the following steps: S1, first, place the PCB to be patched on the conveying structure on the mounting frame 1, and position the PCB; S2, then, support the PCB to be patched below the steel mesh 21, and drive the squeegee assembly 3 to move to one side of the steel mesh 21, and extrude the tin paste onto the steel mesh 21; S3, then, drive the squeegee assembly 3 to scrape the tin paste across the steel mesh 21, so that the tin paste is extruded into the corresponding holes of the steel mesh 21; S4, finally, drive the adjusting assembly to move the squeegee assembly 3 upwards, so that the squeegee assembly 3 moves to the interior of the cleaning assembly 4 for cleaning.

[0035] The above examples are only used to illustrate the technical solutions of the present application, but not to limit the present application; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalent features; and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present application.

Claims

1. An SMT patch device, comprising a mounting frame (1), a mounting frame (1) is fixedly installed in the middle for tin paste printing mounting frame (2), the mounting frame (2) is provided with a steel mesh (21) inside, the mounting frame (1) is provided with a sliding plate (11) for conveying PCB board, characterized in that, Also include: Scraper assembly (3) is slidingly installed above the mounting frame (2), used for printing tin paste on the steel mesh (21), so that the tin paste on the surface of the steel mesh (21) is attached to the PCB board; Cleaning assembly (4) is arranged on one side of the scraper assembly (3), used for cleaning the scraper assembly (3) during tin paste printing; Adjusting assembly, including sliding frame (22), used to drive the scraper assembly (3) to move up and down and left and right; Wherein, the scraper assembly (3) and the cleaning assembly (4) are arranged on one side of the sliding frame (22) and above the mounting frame (2).

2. A SMT patch device according to claim 1, characterized in that The sliding frame (22) is slidingly installed above the mounting frame (2), and the sliding frame (22) is provided with linear motors on both sides for driving the sliding frame (22) to slide on the mounting frame (2).

3. A SMT pick-and-place device according to claim 2, characterized in that The middle part of the sliding frame (22) is fixedly installed with a sliding rail (23), the sliding rail (23) is slidingly installed with a sliding block (25), the side of the sliding block (25) away from the sliding rail (23) is fixedly installed with a trapezoidal rod (26), the scraper assembly (3) is fixedly installed at the end of the trapezoidal rod (26) away from the sliding block (25), and the sliding frame (22) is rotatably installed with a screw rod (24) for driving the sliding block (25) to move up and down, and the sliding frame (22) is internally provided with a driving motor (241) for driving the screw rod (24) to rotate.

4. A SMT pick-and-place device according to claim 3, characterized in that The scraper assembly (3) comprises a mounting plate fixedly installed on the trapezoidal rod (26) and a scraper plate (31) below the mounting plate, a rotating connection shaft (32) is rotatably installed below the mounting plate for rotating connection with the scraper plate (31), a scraper (311) is fixedly installed below the scraper plate (31), and the cleaning assembly (4) is located between the scraper plate (31) and the sliding frame (22).

5. A SMT patch device according to claim 4, characterized in that The side of the mounting plate away from the sliding frame (22) is slidingly installed with an L-shaped plate (34) for adjusting the scraper (311) on the scraper plate (31) to rotate into the cleaning assembly (4).

6. The SMT patch device of claim 1, wherein, The side of the mounting plate away from the sliding frame (22) is provided with a horizontal plate (33), the horizontal plate (33) is slidingly installed on the L-shaped plate (34), the side of the L-shaped plate (34) facing the sliding frame (22) is provided with a gear rack (341), the rotating connection shaft (32) is fixedly installed with a gear (321) for meshing with the gear rack (341), the horizontal plate (33) is fixedly installed with an elastic element (35) above for driving the L-shaped plate (34) to move upward, and the cleaning assembly (4) is fixedly installed with a limiting rod (41) above for limiting the upward movement of the L-shaped plate (34) during the upward movement of the sliding block (25).

7. A SMT patch device according to claim 6, characterized in that The side of the mounting plate away from the sliding frame (22) is provided with a limiting groove for guiding the upward and downward movement of the gear rack (341), and the top of the gear rack (341) abuts against the upper inner wall of the limiting groove.

8. A SMT patch device according to claim 7, characterized in that The cleaning assembly (4) comprises a cleaning box fixedly installed on one side of the sliding frame (22), and a cleaning frame (43) is arranged on the side of the cleaning box facing the scraper plate (31), the opening profile of the cleaning frame (43) is matched with the profile of the scraper plate (31), a reciprocating shaft (433) is slidably installed in the cleaning frame (43), a reciprocating driving piece (42) is arranged on one side of the cleaning frame (43) and used for driving the reciprocating shaft (433) to reciprocate, a plurality of cleaning plates (432) are arranged on the reciprocating shaft (433) at intervals, and the cleaning plates (432) are used for scraping off the tin paste remaining on the surface of the scraper (311).

9. A SMT patch device according to claim 8, characterized in that A plurality of high-pressure nozzles (431) are fixedly installed on the top of the cleaning frame (43), the lower ends of the high-pressure nozzles (431) respectively extend into the cleaning frame (43), the high-pressure nozzles (431) are respectively located between the cleaning plates (432), and the high-pressure nozzles (431) are used for flushing the tin paste remaining on the surface of the scraper (311).

10. A SMT pick-and-place process using the SMT pick-and-place apparatus of claim 1, wherein, The method comprises the following steps: S1, first, the PCB to be processed is placed on the conveying structure on the mounting frame (1), and the PCB is positioned; S2, then, the PCB to be processed is supported below the steel mesh (21), the scraper assembly (3) is driven to move to one side of the steel mesh (21), and the tin paste is extruded onto the steel mesh (21); S3, then, the scraper assembly (3) is driven to scrape the tin paste on the steel mesh (21), so that the tin paste is extruded into the corresponding holes in the steel mesh (21); S4, finally, the adjusting assembly is driven to drive the scraper assembly (3) to move upwards, so that the scraper assembly (3) moves into the cleaning assembly (4) for cleaning.

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