Steel mesh clamp suitable for SMT production

Abstract

The utility model relates to a steel mesh clamp suitable for SMT (Surface Mount Technology) production, which comprises a bottom plate, a right frame strip and a left frame strip which are mutually symmetrical are detachably connected on the bottom plate, a supporting strip is arranged between the right frame strip and the left frame strip, a pressing strip is hinged on the side edge of the bottom plate, and the right frame strip and the left frame strip are detachably connected on the bottom plate. The thickness of the pressing strip, the thickness of the right frame strip and the thickness of the left frame strip are equal, and a pressing strip cover is detachably connected to the upper face of the pressing strip. The circuit board is clamped on the left frame strip and the right frame strip, the middle bottom face of the circuit board abuts against the supporting plate, the steel mesh is clamped and fixed through the pressing strip and the pressing strip cover, and mesh holes of the steel mesh are fixed after being aligned with the position of the circuit board, so that solder paste printing can be achieved. Offline printing of solder paste can be achieved, and the production efficiency of an automatic assembly line is not affected.

Description

Technical Field

[0001] The utility model relates to the technical field of printed circuit boards, in particular to a stencil fixture applicable to SMT production. Background Art

[0002] Surface Mounting Technology (SMT) is a surface assembly technology. It is a circuit assembly technology that mounts leadless or short-lead surface-mounted components on the surface of a printed circuit board or other substrates and is soldered and assembled by methods such as reflow soldering or dip soldering. Currently, advanced electronic products, especially in computer and communication products, have widely adopted SMT technology. Due to the advantages of high line density, light weight, thin thickness, and good bendability, SMT technology is widely used in the production of printed circuit boards.

[0003] The stencil fixture, also known as the SMT template, is a special fixture for printing solder paste in SMT. Its main function is to assist in the deposition of solder paste, aiming to transfer an accurate amount of solder paste to the accurate position on the empty PCB. That is, the printing stencil is a mold for printing solder paste. When printing solder paste, it is spread onto the pads of the PCB board through the openings of the stencil, and then the chip components are fixed through soldering after chip mounting and passing through the furnace.

[0004] For mature products, they are suitable for mass production. On an automated SMT production line, after programming and other settings on the printer, there are corresponding tracks to clamp the circuit board, and there is no need to design an additional fixture for clamping the circuit board. However, for newly developed products, due to immature processes and the like, programming operations cannot be carried out on the automatic production line (which will affect the production efficiency of the entire automatic production line), and only small-scale trial production can be carried out offline. Therefore, a set of stencil fixtures with simple operation is required to print solder paste on the circuit board. Summary of the Invention

[0005] The purpose of the utility model is to provide a stencil fixture applicable to SMT production to solve the problems raised in the above background art.

[0006] To solve the above technical problems, the utility model is realized through the following technical measures: A stencil fixture applicable to SMT production, which includes a bottom plate, on which a symmetrically arranged right frame bar and left frame bar are detachably connected. A support bar is arranged between the right frame bar and the left frame bar. A pressure bar is hinged on the side edge of the bottom plate. The thickness of the pressure bar, the thickness of the right frame bar, and the thickness of the left frame bar are equal. A pressure bar cover is detachably connected to the upper surface of the pressure bar.

[0007] Compared with the prior art, the advantages of the present utility model are as follows: By clamping the circuit board between the left frame bar and the right frame bar, and then placing the support plate on the middle bottom surface, the stencil is clamped and fixed by the pressure bar and the pressure bar cover. After the mesh holes of the stencil are aligned with the position of the circuit board and fixed, the printing of the solder paste can be achieved. This new type of stencil fixture is relatively simple to operate for small-scale trial production of new products, can achieve offline printing of solder paste, and will not affect the production efficiency of the automatic production line.

[0008] As an improvement of the present utility model, a hollow wedge-shaped groove is provided on the bottom plate, and the right frame bar and the left frame bar are fixed on the bottom plate after being tightly attached to the wedge-shaped groove through wedge-shaped pressing blocks. The purpose of selecting this design: The hollow wedge-shaped groove is used to accommodate the wedge-shaped pressing blocks. The bolts pass through the fixing through holes of the wedge-shaped pressing blocks and are then connected to the threaded holes on the right frame bar to achieve fastening.

[0009] As an improvement of the present utility model, right steps and left steps are provided on both sides of the right frame bar. The height of the right step is A, and the height of the left step is B, where A is 1 mm and B is 1.6 mm. The purpose of selecting this design: The right step and the left step are used to clamp the circuit board. Most conventional circuit boards have a thickness of 1 mm and 1.6 mm. Therefore, different step heights are set on both sides of a right frame bar to adapt to two different thicknesses of circuit boards and achieve dual use of one object.

[0010] As an improvement of the present utility model, mounting holes are provided on the bottom plate and the pressure bar, and threaded holes are provided on the pressure bar cover. The purpose of selecting this design: To fix the pressure bar and the pressure bar cover.

[0011] As an improvement of the present utility model, a cavity is provided on the bottom plate. The purpose of selecting this design: To achieve a lightweight design of the bottom plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The drawings constituting a part of the present utility model are used to provide a further understanding of the present utility model. The schematic embodiments of the present utility model and their descriptions are used to explain the present utility model and do not constitute an improper limitation of the present utility model.

[0013] In the drawings:

[0014] Figure 1 is a perspective view of the stencil fixture described in the present utility model.

[0015] Figure 2 is an exploded view of the stencil fixture described in the present utility model.

[0016] Figure 3 is a perspective of the bottom plate described in the present utility model Figure 1 .

[0017] Figure 4The three-dimensional view of the bottom plate described in the present utility model Figure 2 。

[0018] Figure 5 The three-dimensional view of the right frame bar described in the present utility model

[0019] Figure 6 The three-dimensional view of the wedge-shaped pressing block described in the present utility model

[0020] Figure 7 The three-dimensional view of the pressing bar described in the present utility model

[0021] Figure 8 The three-dimensional view of the pressing bar cover described in the present utility model

[0022] Explanation of reference numerals: 1, bottom plate; 2, right frame bar; 3, left frame bar; 4, support bar; 5, pressing bar; 6, pressing bar cover; 7, wedge-shaped groove; 8, wedge-shaped pressing block; 9, right step; 10, left step; 11, mounting hole; 12, threaded hole; 13, cavity; 14, bolt; 15, circuit board; 16, steel mesh; 17, hinge sleeve; 18, fixed through hole Detailed implementation manners

[0023] The preferred embodiments of the present utility model will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present utility model, and are not used to limit the present utility model

[0024] Embodiment 1

[0025] Please refer to Figure 1 -8

[0026] A steel mesh fixture applicable to SMT production provided in this embodiment includes a bottom plate 1, a symmetrically arranged right frame bar 2 and a left frame bar 3 are detachably connected to the bottom plate 1, a support bar 4 is arranged between the right frame bar 2 and the left frame bar 3, a pressing bar 5 is hinged to the side edge of the bottom plate 1 through a hinge sleeve 17, the thicknesses of the pressing bar 5, the right frame bar 2 and the left frame bar 3 are equal, and a pressing bar cover 6 is detachably connected to the pressing bar 5

[0027] In the embodiment of the present utility model application, please refer to Figure 4 (the reverse side of the same part as Figure 3 ), a hollow wedge-shaped groove 7 is arranged on the bottom plate 1, and the right frame bar 2 and the left frame bar 3 are fixed on the bottom plate 1 after being pressed against the wedge-shaped groove 7 through a wedge-shaped pressing block 8. This hollow wedge-shaped groove 7 is used to accommodate the wedge-shaped pressing block 8. The bolt 14 passes through the fixed through hole 18 of the wedge-shaped pressing block 8 and then is connected to the threaded hole 12 on the right frame bar 2 to achieve fastening. Since it is a conical structure, the contact area is relatively large and it is not easy to loosen after being fixed

[0028] In the embodiments of the present utility model application, please refer to Figure 5 , on both sides of the right frame bar 2, there are a right step 9 and a left step 10. The height of the right step 9 is A, and the height of the left step 10 is B. Among them, A is 1 mm and B is 1.6 mm. In actual application, the right step 9 and the left step 10 are used to clamp the circuit board 15. The thicknesses of conventional circuit boards 15 are mostly 1 mm and 1.6 mm. Therefore, steps with different heights are set on both sides of a right frame bar 2 to adapt to two different thicknesses of circuit boards 15, achieving dual use of one object. Moreover, the bottom end of the step of the right frame bar 2 is a sealed edge design, which is used for the limit in the Y direction of the circuit board 15.

[0029] In the embodiments of the present utility model application, please refer to Figure 7 and Figure 8 , on the bottom plate 1 and the pressure bar 5, there are installation holes 11, and on the pressure bar cover 6, there are threaded holes 12. During production, a steel mesh 16 is clamped between the pressure bar 5 and the pressure bar cover 6. After the mesh holes of the steel mesh 16 are aligned with the positions of the circuit board 15, screws are used to fix the pressure bar 5 and the pressure bar cover 6. It should be noted that a compression spring can also be used between the pressure bar cover 6 and the pressure bar 5 to achieve the press-fitting and fixing of the steel mesh.

[0030] In the embodiments of the present utility model application, please refer to Figure 3 , a cavity 13 is provided on the bottom plate 1. A lightweight design of the bottom plate 1 is achieved.

[0031] In the embodiments of the present utility model application, please refer to Figure 6 , Figure 6 is a three-dimensional view of the wedge-shaped pressing block 8 of the present utility model, in which a fixing through hole 18 is provided in the middle. After the bolt 14 passes through the fixing through hole 18, it is then connected and fixed to the threaded hole 12 behind. In the embodiments of the present utility model application, please refer to Figure 2 , there are three sets of bolts 14, which respectively pass through three wedge-shaped pressing blocks 8 and are threadedly connected and fixed to the right frame bar 2, the right frame bar 2, and the support bar 4.

[0032] A steel mesh fixture applicable to SMT production provided in this embodiment, during normal use, place the circuit board 15 on the steps of the right frame bar 2 and the left frame bar 3, then use bolts 14 to fix the right frame bar 2, the left frame bar 3, and the support bar 4. Then, pre-clamp the steel mesh 16 between the pressure bar 5 and the pressure bar cover 6. After aligning the mesh holes of the steel mesh 16 with the positions of the circuit board 15, completely fix the pressure bar 5 and the pressure bar cover 6. Since the thicknesses of the pressure bar 5, the right frame bar 2, and the left frame bar 3 are equal to each other, a flat printing surface is formed under the steel mesh 16, and thus the printing of solder paste can be achieved.

[0033] The beneficial effects of the present utility model are as follows: By clamping the circuit board 15 between the left frame bar 3 and the right frame bar 2, and then placing the support plate on the middle bottom surface, the stencil 16 is clamped and fixed by the pressure bar 5 and the pressure bar cover 6. After the mesh holes of the stencil 16 are aligned with the position of the circuit board 15 and fixed, the printing of solder paste can be achieved. This new type of stencil fixture is relatively simple to operate for small-scale trial production of new products, can achieve offline printing of solder paste, and will not affect the production efficiency of the automatic production line.

[0034] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "vertical", "upper", "lower", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present utility model.

[0035] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", "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 mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0036] Finally, it should be noted that the above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A steel mesh fixture suitable for SMT production, characterized by: The invention comprises a bottom plate (1), on which a right frame bar (2) and a left frame bar (3) are detachably connected and symmetrical to each other, a support bar (4) is arranged between the right frame bar (2) and the left frame bar (3), a pressure bar (5) is hinged on the side of the bottom plate (1), the thickness of the pressure bar (5), the thickness of the right frame bar (2), and the thickness of the left frame bar (3) are equal, and a pressure bar cover (6) is detachably connected to the pressure bar (5).

2. The steel mesh fixture suitable for SMT production according to claim 1 is characterized in that: The bottom plate (1) is provided with a hollow wedge-shaped groove (7), and the right frame bar (2) and the left frame bar (3) are fixed to the bottom plate (1) by being tightly attached to the wedge-shaped groove (7) via a wedge-shaped pressing block (8).

3. The steel mesh fixture suitable for SMT production according to claim 1 is characterized in that: A right step (9) and a left step (10) are provided on both sides of the right frame bar (2), the height of the right step (9) is A, and the height of the left step (10) is B, wherein A is 1 mm and B is 1.6 mm.

4. The steel mesh fixture suitable for SMT production according to claim 1 is characterized in that: The bottom plate (1) and the pressure strip (5) are provided with mounting holes (11), and the pressure strip cover (6) is provided with threaded holes (12).

5. The steel mesh fixture suitable for SMT production according to claim 1 is characterized in that: The bottom plate (1) is provided with a cavity (13).

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