A printing jig for SMT printed circuit board

Abstract

The utility model relates to SMT printing technical field discloses a kind of printing jigs of SMT printed circuit board, including pedestal, the upper portion of the pedestal is provided with limiting tray, installation slot is provided on the limiting tray;And the pedestal is provided with two No. The fixed seat of one side of limiting tray, each No. The fixed seat of one is movably provided with two groups of anti-warping edge mechanism, each group of the anti-warping edge mechanism includes slide plate and No. The fixed seat of two that is set on slide plate, No. The fixed seat is rotatably connected with rotating seat;Replaceable limiting tray and pedestal positioning pin cooperation structure are used, under the premise of circuit board circumferential positioning, four corners of circuit board can be pressed using pressing plate, to avoid the corner of circuit board to warp up;Different circuit board length can be adapted by the sliding of slide plate in No. The locking of one positioning bolt stops, the sliding cooperation of sliding sleeve and pressing plate No. The positioning of two positioning bolts can calibrate width direction pressing position, ensure that four corners are stably pressed.

Description

Technical Field

[0001] This utility model relates to the field of SMT printing technology, and in particular to a printing fixture for SMT printed circuit boards. Background Technology

[0002] SMT printing fixtures (also known as stencil fixtures) are precision tools used in SMT production for printing solder paste / adhesive. They are typically thin stainless steel sheets with custom-designed perforations, the positions of which are precisely matched to the PCB pads. Their core function is to achieve precise positioning and printing of solder paste through high-precision perforations, preventing solder paste misalignment or contamination of non-pad areas; simultaneously, the size and thickness of the perforations control the amount of solder paste transferred, preventing defects such as bridging and cold solder joints.

[0003] However, the fixture lacks sufficient positioning stability for the circuit board. Although it has a positioning and clamping structure, the circuit board is subject to compression and is affected by its own material, causing the corners to easily lift up. This can lead to defects such as poor soldering and short circuits in electronic components due to deviations in the solder paste printing position during the printing process, seriously affecting production efficiency and product yield. Utility Model Content

[0004] Purpose of the utility model: The purpose of this utility model is to provide a printing fixture for SMT printed circuit boards to solve the above-mentioned shortcomings in the prior art.

[0005] Technical solution: A printing fixture for SMT printed circuit boards includes a base, a limiting tray is provided above the base, and a mounting groove is provided on the limiting tray;

[0006] Furthermore, the base is provided with two No. 1 fixed seats located on both sides of the limiting tray. Each No. 1 fixed seat is movably provided with two sets of anti-warping mechanisms. Each set of anti-warping mechanisms includes a sliding plate and a No. 2 fixed seat provided on the sliding plate. A rotating seat is rotatably connected to the No. 2 fixed seat. The rotating seat is connected to a sliding sleeve through a connecting rod. A pressure plate is slidably connected inside the sliding sleeve.

[0007] The slide plate is also equipped with an L-shaped baffle to limit the position of the sliding sleeve.

[0008] As a further description of the above technical solution: the sliding sleeve is provided with a threaded groove, and the internal thread of the threaded groove is connected to a second positioning bolt. The pressure plate is provided with a number of second matching grooves that are equidistantly arranged and adapted to the second positioning bolt.

[0009] As a further description of the above technical solution: the anti-warping mechanism also includes a spiral spring box disposed on the second fixed base, and a spiral spring is disposed inside the spiral spring box;

[0010] Furthermore, the rotating base is provided with a rotating shaft, one end of the spiral spring is connected to the spiral spring box, and the other end of the spiral spring is connected to the rotating shaft.

[0011] As a further description of the above technical solution: A sliding groove is formed on the top surface of the first fixed seat, and the sliding plate is slidably connected inside the first sliding groove;

[0012] Furthermore, the slide plate is provided with a connecting block, the connecting block is provided with a second threaded groove, the inside of the second threaded groove is connected to a first positioning bolt, and the first fixing seat is provided with a number of first fitting grooves arranged at equal intervals and adapted to the first positioning bolt.

[0013] As a further description of the above technical solution: the slide plate is provided with a second slide groove, the interior of the second slide groove is provided with two slide shafts, and the L-shaped baffle is slidably connected to the slide shafts. A return spring is also sleeved on the outside of the slide shafts, and the return spring is placed between the L-shaped baffle and the inner wall of the second slide groove.

[0014] As a further description of the above technical solution: the rotating base is provided with a first limiting piece, and the second fixed base is provided with a second limiting piece that cooperates with the first limiting piece.

[0015] As a further description of the above technical solution: the base is provided with four positioning pins, and the positioning pins are arranged symmetrically in pairs;

[0016] The limiting tray has positioning holes that are compatible with the positioning pins.

[0017] As a further description of the above technical solution: the No. 1 slide groove is arranged in a continuous manner with several No. 1 adapter grooves.

[0018] Beneficial effects: The structure of replacing the limit tray and the base positioning pin allows for circumferential positioning of the circuit board, while the pressure plate can press down on the four corners of the circuit board to prevent the corners of the circuit board from lifting up.

[0019] In addition, the sliding of the slide plate in the first slide groove and the locking of the first positioning bolt can accommodate different circuit board lengths. The sliding of the sliding sleeve and the pressure plate, together with the positioning of the second positioning bolt, can calibrate the pressing position in the width direction, ensuring stable pressing at the four corners, reducing quality problems caused by the corners of the circuit board lifting during the solder paste printing process, and improving the production efficiency and product yield of the SMT printing process. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall three-dimensional structure of this utility model;

[0021] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0022] Figure 3 This is a partial three-dimensional structural schematic diagram of the present invention;

[0023] Figure 4 for Figure 3 Enlarged view of point B in the middle;

[0024] Figure 5 This is an exploded three-dimensional structural view of the present invention.

[0025] Legend:

[0026] 1. Base; 2. Fixed base No. 1; 3. Slide groove No. 1; 4. Adaptor groove No. 1; 5. Slide plate; 6. Fixed base No. 2; 7. Connecting block; 8. Positioning bolt No. 1; 9. Spring box; 10. Scroll spring; 11. Rotary shaft; 12. Rotary seat; 13. Connecting rod; 14. Limiting plate No. 1; 15. Limiting plate No. 2; 16. Sliding sleeve; 17. Positioning bolt No. 2; 18. Adaptor groove No. 2; 19. Pressure plate; 20. Slide groove No. 2; 21. L-shaped baffle; 22. Sliding shaft; 23. Return spring; 24. Positioning pin; 25. Limiting tray; 26. Positioning hole; 27. Mounting groove. Detailed Implementation

[0027] To make the technical solution of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Reference Figures 1-5 A printing fixture for SMT printed circuit boards includes a base 1, with a limiting tray 25 disposed above the base 1. The limiting tray 25 is provided with a mounting groove 27. It should be noted that the mounting groove 27 is used to place the circuit board, and the shape and size of the mounting groove 27 are the same as the shape and size of the circuit board. The circuit board is positioned around the perimeter. Different specifications of circuit boards need to be adapted to mounting grooves 27 of different shapes and sizes, but the size and shape of the limiting tray 25 remain unchanged.

[0029] Furthermore, the base 1 is provided with two first fixing seats 2 located on both sides of the limiting tray 25. Each first fixing seat 2 is movably provided with two sets of anti-warping mechanisms. Each set of anti-warping mechanisms includes a sliding plate 5 and a second fixing seat 6 provided on the sliding plate 5. A rotating seat 12 is rotatably connected to the second fixing seat 6. The rotating seat 12 is connected to a sliding sleeve 16 through a connecting rod 13. A pressure plate 19 is slidably connected inside the sliding sleeve 16 for pressing above the four corners of the circuit board. Rubber blocks are provided at the contact points between the pressure plate 19 and the circuit board to reduce collisions between them during contact. It should be noted that the rubber blocks can accommodate minor thickness differences that occur during the circuit board production process. Also, this solution does not have a thickness adaptation setting for the circuit board because the circuit boards printed in this solution are all of the same thickness.

[0030] The slide plate 5 is also provided with an L-shaped baffle 21 for limiting the position of the sliding sleeve 16.

[0031] Specifically, after the circuit board is installed, the connecting rod 13 and the L-shaped baffle 21 can be used to limit the four corners of the circuit board below by the four pressure plates 19, so as to avoid the solder paste printing position deviation during the solder paste printing process, which would cause problems such as poor soldering and short circuits when soldering electronic components later.

[0032] Furthermore, the sliding sleeve 16 is provided with a threaded groove, and the internal thread of the threaded groove is connected to a second positioning bolt 17. It should be noted that the second positioning bolt 17 has anti-slip texture on the side wall near the top, which can be directly gripped and rotated by hand. The pressure plate 19 has several second adaptation slots 18 arranged at equal intervals and adapted to the second positioning bolts 17. The relative position of the pressure plate 19 and the sliding sleeve 16 can be adjusted according to the width of the circuit board, so that the end of the pressure plate 19 can press against the top of the circuit board. Then, the second positioning bolt 17 is rotated and inserted into the second adaptation slot 18 directly below for locking and positioning. Thus, it is convenient to adjust the position of the pressure plate 19 according to circuit boards of different sizes, improving the adaptability of the printing fixture.

[0033] Furthermore, the anti-warping mechanism also includes a spiral spring box 9 disposed on the second fixed base 6, and a spiral spring 10 is disposed inside the spiral spring box 9;

[0034] Furthermore, a rotating shaft 11 is provided on the rotating base 12. One end of the spiral spring 10 is connected to the spiral spring box 9, while the other end of the spiral spring 10 is connected to the rotating shaft 11. Specifically, during the process of removing the L-shaped baffle 21, the rotating shaft 11 is driven to rotate the base 1 under the action of the spiral spring 10. The rotating shaft 11 drives the rotating base 12 to rotate in the opposite direction and drives the connecting rod 13 to reset, so that the pressure plate 19 is disengaged from the top of the circuit board.

[0035] Furthermore, a first groove 3 is provided on the top surface of the first fixed base 2, and the slide plate 5 is slidably connected inside the first groove 3;

[0036] Furthermore, the slide plate 5 is provided with a connecting block 7, the connecting block 7 is provided with a threaded groove 2, the threaded groove 2 is internally threaded with a positioning bolt 8, and the first fixing seat 2 is provided with a number of first fitting grooves 4 arranged at equal intervals and adapted to the first positioning bolt 8.

[0037] Specifically, since the circuit boards are of different sizes, their lengths also vary. Therefore, the position of the slide plate 5 inside the first slide groove 3 can be adjusted, and then the first positioning bolt 8 can be inserted into the first adapter groove 4 directly below by rotating it to limit the slide plate 5, thereby adapting it to circuit boards of different lengths.

[0038] Furthermore, the slide plate 5 is provided with a second slide groove 20, and two slide shafts 22 are provided inside the second slide groove 20. The L-shaped baffle 21 is slidably connected to the slide shafts 22, and a return spring 23 is sleeved on the outside of the slide shafts 22. The return spring 23 is placed between the L-shaped baffle 21 and the inner wall of the second slide groove 20. By pulling the L-shaped baffle 21 to slide on the slide shafts 22, the restriction on the slide sleeve 16 can be released. Afterwards, releasing the L-shaped baffle 21 can push the L-shaped baffle 21 to reset under the action of the return spring 23.

[0039] Furthermore, the rotary seat 12 is provided with a first limiting piece 14, and the second fixed seat 6 is provided with a second limiting piece 15 that works in conjunction with the first limiting piece 14. After the L-shaped baffle 21 releases the restriction on the sliding sleeve 16, it can rotate the connecting rod 13 on the rotary seat 12 to the starting position after it has been reset and rotated 90 degrees. By using the limiting pieces 14 and 15, the rotary seat 12 will not shake after it has been reset.

[0040] Furthermore, the base 1 is provided with four positioning pins 24, and the positioning pins 24 are arranged symmetrically in pairs.

[0041] The limiting tray 25 is provided with a positioning hole 26 that matches the positioning pin 24, which makes it easy to position and install the limiting tray 25 above the base 1.

[0042] Furthermore, the first sliding groove 3 is arranged in a continuous manner with several first adapting grooves 4.

[0043] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A printing fixture for SMT printed circuit boards, comprising a base (1), characterized in that, A limiting tray (25) is provided above the base (1), and an installation groove (27) is provided on the limiting tray (25). Furthermore, the base (1) is provided with two No. 1 fixing seats (2) located on both sides of the limiting tray (25), and each No. 1 fixing seat (2) is movably provided with two sets of anti-warping mechanisms; Each anti-warping mechanism includes a slide plate (5) and a second fixed seat (6) set on the slide plate (5). A rotating seat (12) is rotatably connected to the second fixed seat (6). The rotating seat (12) is connected to a sliding sleeve (16) through a connecting rod (13). A pressure plate (19) is slidably connected inside the sliding sleeve (16). The slide plate (5) is also provided with an L-shaped baffle (21) for limiting the position of the slide sleeve (16).

2. The printing fixture for an SMT printed circuit board according to claim 1, characterized in that, The sliding sleeve (16) is provided with a threaded groove, and the internal thread of the threaded groove is connected to a second positioning bolt (17). The pressure plate (19) is provided with several second matching grooves (18) that are equidistantly arranged and adapted to the second positioning bolt (17).

3. The printing fixture for an SMT printed circuit board according to claim 1, characterized in that, The anti-warping mechanism also includes a spiral spring box (9) set on the second fixed base (6), and a spiral spring (10) is provided inside the spiral spring box (9). The rotating base (12) is provided with a rotating shaft (11), one end of the spiral spring (10) is connected to the spiral spring box (9), and the other end of the spiral spring (10) is connected to the rotating shaft (11).

4. The printing fixture for an SMT printed circuit board according to claim 1, characterized in that, A first groove (3) is provided on the top surface of the first fixed seat (2), and the slide plate (5) is slidably connected to the inside of the first groove (3); Furthermore, the sliding plate (5) is provided with a connecting block (7), the connecting block (7) is provided with a threaded groove II, the threaded groove II is internally threaded with a positioning bolt (8), and the first fixing seat (2) is provided with several first fitting grooves (4) arranged at equal intervals and adapted to the first positioning bolt (8).

5. The printing fixture for an SMT printed circuit board according to claim 1, characterized in that, The slide plate (5) is provided with a second slide groove (20), and two slide shafts (22) are provided inside the second slide groove (20). The L-shaped baffle (21) is slidably connected to the slide shafts (22). A return spring (23) is also sleeved on the outside of the slide shafts (22), and the return spring (23) is placed between the L-shaped baffle (21) and the inner wall of the second slide groove (20).

6. The printing fixture for an SMT printed circuit board according to claim 1, characterized in that, The rotating base (12) is provided with a first limiting piece (14), and the second fixing base (6) is provided with a second limiting piece (15) that works in conjunction with the first limiting piece (14).

7. The printing fixture for an SMT printed circuit board according to claim 1, characterized in that, The base (1) is provided with four positioning pins (24), and the positioning pins (24) are arranged symmetrically in pairs; The limiting tray (25) is provided with a positioning hole (26) that is compatible with the positioning pin (24).

8. The printing fixture for an SMT printed circuit board according to claim 4, characterized in that, The first slide (3) is arranged in a continuous manner with several first adapter slots (4).

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