Stepped steel mesh with controllable tin immersion thickness

Abstract

The utility model discloses a step steel mesh capable of controlling the tin immersion thickness, which comprises a printing plate, and the bottom of the printing plate is flat; the plurality of tin immersion tables are formed on the surface of the printed board, and the plurality of tin immersion tables are formed by processing the surface of the printed board according to the specification of a matched printed circuit bonding pad so as to form step structures with different heights; and the plurality of tin immersion holes are arranged above the plurality of tin immersion platforms and penetrate through the printing plate, the plurality of tin immersion holes are divided into a plurality of specifications according to the specifications of the matched printed circuit bonding pads, and the plurality of tin immersion holes with the same specification are positioned on the plurality of tin immersion platforms with the same height. According to the utility model, the integrally formed stepped steel mesh is adopted, the tin immersion tables with different heights are processed on the printing plate according to the specifications of the printed circuit pads, and the corresponding tin immersion holes are processed on the corresponding tin immersion tables; therefore, during printing, the solder paste is controlled to form a tin point matched with a pin of the component according to the thickness of the tin immersion table and the size of the tin immersion hole, and the welding quality of the component is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit board manufacturing, in particular to a step steel mesh with controllable tin-immersion thickness. Background Art

[0002] The steel mesh is a special SMT mold whose main function is to help the deposition of solder paste. Its purpose is to transfer the exact amount of solder paste to the exact position on the printed circuit pad.

[0003] At present, the commonly used steel mesh is usually a flat steel mesh, that is, the flat steel mesh is laid flat on the printed circuit pad and fixed, and the solder paste is scraped back and forth on the surface of the flat steel mesh so that the solder paste falls from the holes of the steel mesh onto the printed circuit pad. After separation, the solder paste is deposited on the printed circuit pad at the corresponding position. Although this flat steel mesh can complete the tinning step, the thickness of the area where each hole of the flat steel mesh is located is consistent, and the thickness of the deposited solder paste is the same. For some special components, such as connectors, which have larger pins, insufficient solder paste deposition is likely to cause cold soldering or insufficient soldering after soldering.

[0004] Therefore, it is difficult to control the increase of the deposition thickness of the solder paste at the corresponding position by using a flat steel mesh in the existing tinning process, which may easily lead to cold solder joints or insufficient solder joints in some components. Utility Model Content

[0005] The utility model aims to provide a stepped steel mesh with controllable tinning thickness, so as to solve the technical problem in the prior art that the flat steel mesh has a uniform thickness and it is difficult to control the tinning thickness of the solder paste at a specific position, thus affecting the welding quality.

[0006] In order to solve the above technical problems, the utility model specifically provides the following technical solutions:

[0007] A step steel mesh with controllable tin-immersion thickness, comprising:

[0008] A printing plate, wherein the bottom of the printing plate is arranged flat;

[0009] A plurality of soldering stations are formed on the surface of the printed board, and the plurality of soldering stations are processed on the surface of the printed board according to the specifications of the matching printed circuit pads to form a stepped structure with different heights;

[0010] A plurality of tin sinking holes are arranged above the plurality of tin sinking platforms and penetrate the printed board. The plurality of tin sinking holes are divided into a plurality of specifications according to the specifications of the matching printed circuit pads, and the plurality of tin sinking holes of the same specification are located on the plurality of tin sinking platforms at the same height;

[0011] When the printed board is covered on the matching printed circuit pad for printing, the plurality of tinning holes on the tinning platform at different heights form solder pastes of different thicknesses on the printed circuit pad.

[0012] As a preferred solution of the utility model, the plurality of tinning stations include at least one basic station to print and obtain a basic tinning thickness;

[0013] The parts of the plurality of tin sinking stations that are higher than the basic stations are elevated stations, and the elevated heights of the plurality of elevated stations are determined according to the specifications of the matching printed circuit pads;

[0014] The basic position is arranged on the printing board, and the heightened position is arranged on the basic position or independently arranged on the printing board.

[0015] As a preferred solution of the utility model, the plurality of tin sinking holes at least include a plurality of basic hole positions, so as to obtain basic tin sinking points by printing;

[0016] The portions of the plurality of tin-immersion holes whose diameters are larger than the diameters of the basic holes are enlarged holes, and the diameter enlargement values ​​of the plurality of enlarged holes are determined according to the specifications of the matching printed circuit pads;

[0017] The basic hole position is arranged on the basic platform position, and the enlarged hole position is arranged on the matching heightened platform position.

[0018] As a preferred solution of the utility model, the side walls around the tinning table are formed with landslides, and there is a smooth transition between the landslide and the surface of the tinning table, and there is a smooth transition between two adjacent landslides.

[0019] As a preferred solution of the utility model, a tin sinking tank is centrally arranged on the printing plate, and the plurality of tin sinking platforms and the plurality of tin sinking holes are all located in the tin sinking tank, and the depth of the tin sinking tank is greater than or equal to the highest height of the plurality of tin sinking platforms;

[0020] The two side walls of the tin sinking tank facing the solder paste being scraped and printed are formed with material slopes, and the side walls adjacent to the material slopes are vertically arranged to limit the lateral flow of the solder paste, and the material slopes are smoothly transitioned to the bottom of the tin sinking tank and the surface of the printing plate respectively.

[0021] As a preferred solution of the utility model, an anti-overflow frame is provided on the printing plate, and the anti-overflow frame is placed around the tin sinking tank, and the distance between two opposite side walls of the anti-overflow frame is equal to the distance between two vertical side walls of the tin sinking tank, and the distance between the other two opposite side walls of the anti-overflow frame is greater than the distance between the upper edges of the two material slopes.

[0022] Compared with the prior art, the utility model has the following beneficial effects:

[0023] The utility model adopts an integrally formed stepped steel mesh, forms tinning platforms of different heights on the printed board according to the specifications of the printed circuit pads, and forms corresponding tinning holes on the corresponding tinning platforms, so that the solder paste is controlled to form tin points matching the pins of the components according to the thickness of the tinning platforms and the size of the tinning holes during printing, thereby improving the quality of component welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the implementation of the utility model or the technical solution in the prior art, the following is a brief introduction to the drawings required for the implementation or the prior art description. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0025] Figure 1 A schematic diagram of the structure of a stepped steel mesh with controllable tin-immersion thickness is provided for an embodiment of the utility model;

[0026] Figure 2 A schematic diagram of the structure of a tinning tank portion of a stepped steel mesh with controllable tinning thickness is provided for an embodiment of the utility model.

[0027] The numbers in the figure represent the following:

[0028] 1-printing board; 2-tinning station; 3-tinning hole;

[0029] 11-tin sink; 12-material slope; 13-anti-overflow frame; 21-base platform; 22-heightening platform; 23-slide; 31-base hole; 32-enlarged hole. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0031] like Figure 1 , Figure 2 As shown, the utility model provides a step steel mesh with controllable tin-immersion thickness, comprising:

[0032] Printing board 1, the bottom of the printing board 1 is arranged flat;

[0033] A plurality of soldering stations 2 are formed on the surface of the printed board 1. The plurality of soldering stations 2 are processed on the surface of the printed board 1 according to the specifications of the matching printed circuit pads to form a stepped structure with different heights.

[0034] A plurality of tin sinking holes 3 are arranged above the plurality of tin sinking platforms 2 and penetrate the printed board 1. The plurality of tin sinking holes 3 are divided into a plurality of specifications according to the specifications of the matching printed circuit pads, and the plurality of tin sinking holes 3 of the same specification are located on the plurality of tin sinking platforms 2 of the same height;

[0035] When the printed board 1 is printed on the matching printed circuit pad, the multiple tinning holes 3 on the tinning platform 2 at different heights form solder pastes of different thicknesses on the printed circuit pad.

[0036] The stepped steel mesh of the present embodiment is mainly processed on the surface of a conventional printed board 1 according to the specifications of the matching printed circuit pads, and the corresponding tinning tables 2 are designed with different heights according to the tinning thickness required by the component pin specifications, and tinning holes 3 corresponding to the component pin specifications are set on the corresponding tinning tables 2, so that solder pastes of different thicknesses can be formed on the same set of printed circuit pads to improve the firmness of component welding, and the tinning tables 2 and tinning holes 3 on the printed board 1 are made in the process of step steel mesh processing, so that different stepped steel meshes are designed for different printed circuit pads, so as to achieve the purpose of controllable tin thickness on printed circuit pads of various specifications.

[0037] Compared with the existing flat steel mesh, the stepped steel mesh of this embodiment can form solder paste of different thicknesses on the printed circuit pad through the tinning table 2 of different heights. Therefore, according to the design specifications of the printed circuit pad and the size of the pins of the components to be soldered, a matching tinning table 2 is designed so that the tinning thickness can match the size of the component pins, thereby improving the firmness of the welding.

[0038] Based on the above embodiments, preferred embodiments of the tinning station 2 and the tinning hole 3 are provided below.

[0039] like Figure 1 , Figure 2 As shown, the plurality of tin sinking stations 2 include at least one basic station 21 for printing to obtain a basic tin sinking thickness;

[0040] The part of the multiple tin sinking stations 2 that is higher than the basic station 21 is the elevated station 22, and the elevated heights of the multiple elevated stations 22 are determined according to the specifications of the matching printed circuit pads;

[0041] The base stage 21 is disposed on the printing board 1 , and the heightened stage 22 is disposed on the base stage 21 or independently disposed on the printing board 1 .

[0042] Specifically, the basic platform 22 is the tinning platform 2 required for the minimum tinning thickness. Based on this, the tinning platform 2 with a required tinning thickness greater than the basic thickness is used as an increased platform 22. The increased value of each increased platform 22 is determined by the specifications of the actual printed circuit pad. Adjacent basic platforms 21 or adjacent increased platforms 22 can be connected to form a whole, reducing the difficulty of processing.

[0043] For some independent large components, which are located in a separate area of ​​the printed circuit pads, the corresponding heightened positions 22 are independently arranged on the printed board 1. Of course, all printed circuit pads can be covered by the basic positions 21 first, and then the corresponding heightened positions 22 are formed on the basis of the basic positions 21 according to the corresponding positions.

[0044] In addition, if Figure 1 , Figure 2 As shown, the plurality of tin sinking holes 3 at least include a plurality of basic hole positions 31, so as to obtain basic tin sinking points by printing;

[0045] The portion of the multiple tin-immersion holes 3 whose diameter is larger than the diameter of the basic hole 31 is the enlarged hole 32, and the diameter enlargement values ​​of the multiple enlarged holes 32 are determined according to the specifications of the matching printed circuit pads;

[0046] The basic hole position 31 is arranged on the basic platform position 21 , and the enlarged hole position 32 is arranged on the matching heightened platform position 22 .

[0047] Generally speaking, the pins of components are relatively large, and the area and thickness of the solder paste required for immersion tin need to be increased accordingly. Therefore, the basic hole position 31 in the immersion tin hole 3 is designed according to the minimum component pin, and the enlarged hole position 32 is further matched and adjusted based on the basic hole position 31 according to the corresponding component pin.

[0048] During the printing process, the soft brush of the solder paste needs to brush back and forth across the soldering station 2. Therefore, in order to enable the soft brush to smoothly apply the solder paste, the following preferred embodiments are provided.

[0049] like Figure 1 , Figure 2 As shown, a landslide 23 is formed on the side walls around the tinning platform 2. There is a smooth transition between the landslide 23 and the surface of the tinning platform 2, and there is a smooth transition between two adjacent landslides 23.

[0050] Specifically, the side wall of the tinning table 2 is designed with a landslide 23, so that the surface of the tinning table 2 and the printed board 1 or the basic platform 21 and the elevated platform 22 have a smooth transition, and there is a smooth transition between two adjacent landslides 23, so that the soft brush applying solder paste can pass through the tinning table 2 more smoothly, and the wear of the soft brush by the tinning table 2 is relatively small.

[0051] During the solder paste application process, the solder paste fluid easily overflows to the sides of the soft brush, causing part of the solder paste to be distributed in the non-printing area on the printing plate 1, resulting in solder paste waste. Therefore, the following preferred embodiments are provided to limit the overflow of the solder paste during application.

[0052] like Figure 2 As shown, a tin sinking tank 11 is centrally arranged on the printed board 1, and a plurality of tin sinking stations 2 and a plurality of tin sinking holes 3 are all located in the tin sinking tank 11, and the depth of the tin sinking tank 11 is greater than or equal to the highest height of the plurality of tin sinking stations 2;

[0053] The two side walls of the tin sink 11 facing the solder paste are formed with material slopes 12, and the side walls adjacent to the material slopes 12 are vertically arranged to limit the lateral flow of the solder paste, and the material slopes 12 are smoothly transitioned to the bottom of the tin sink 11 and the surface of the printed board 1 respectively.

[0054] Specifically, a tinning tank 11 is provided on the printing board 1, and the tinning platform 2 is formed in the tinning tank 11. When the soft brush applies the solder paste through the tinning tank 11, the solder paste overflowing laterally from the soft brush is blocked by the side wall of the tinning tank 11, thereby avoiding further diffusion to the non-printing area of ​​the printing board 1.

[0055] In order to facilitate smooth brushing of solder paste and reduce residual waste, material slopes 12 are formed on both sides of the soldering tank 11 along the brushing line. After each brushing is completed, the solder paste is temporarily stored on the printed board 1 through the material slopes 12 for subsequent brushing.

[0056] In order to make the brushing more comprehensive, the width of the tin sinking tank 11 can be equal to the width of the soft brush, so that all the solder paste in the tin sinking tank 11 can be scraped to avoid waste.

[0057] Furthermore, if Figure 2 As shown, an anti-overflow frame 13 is provided on the printing plate 1, and the anti-overflow frame 13 is placed around the tin sink 11, and the distance between two opposite side walls of the anti-overflow frame 13 is equal to the distance between two vertical side walls of the tin sink 11, and the distance between the other two opposite side walls of the anti-overflow frame 13 is greater than the distance between the upper edges of the two material slopes 12.

[0058] Specifically, when the solder paste is brushed and scraped from the material slope 12 onto the surface of the printed board 1, the solder paste easily overflows from both sides of the soft brush onto the printed board 1, and an anti-overflow frame 13 is provided on the printed board 1 to surround the tin sink 11 and seal the two material slopes 12, so that the brushing action is carried out within the anti-overflow frame 13, thereby effectively avoiding the overflow and waste of solder paste.

[0059] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present application.

Claims

1. A step steel mesh with controllable tin thickness, characterized in that: include: A printing plate (1), wherein the bottom of the printing plate (1) is arranged flat; A plurality of soldering platforms (2) are formed on the surface of the printed board (1), and the plurality of soldering platforms (2) are processed on the surface of the printed board (1) according to the specifications of the matching printed circuit pads to form a stepped structure with different heights; A plurality of tin sinking holes (3) are arranged above the plurality of tin sinking platforms (2) and penetrate the printed board (1); the plurality of tin sinking holes (3) are divided into a plurality of specifications according to the specifications of the matching printed circuit pads, and the plurality of tin sinking holes (3) of the same specification are located on the plurality of tin sinking platforms (2) at the same height; When the printed board (1) is printed on the matching printed circuit pad, the plurality of tinning holes (3) on the tinning platform (2) at different heights form solder pastes of different thicknesses on the printed circuit pad.

2. The step steel mesh with controllable tin-immersion thickness according to claim 1, characterized in that: The plurality of tin sinking stations (2) include at least one basic station (21) for printing to obtain a basic tin sinking thickness; The parts of the plurality of solder sinking platforms (2) that are higher than the basic platform (21) are elevated platforms (22), and the elevated heights of the plurality of elevated platforms (22) are determined according to the specifications of the matching printed circuit pads; The basic platform (21) is arranged on the printing plate (1), and the elevated platform (22) is arranged on the basic platform (21) or is independently arranged on the printing plate (1).

3. The step steel mesh with controllable tin thickness according to claim 2, characterized in that: The plurality of tin-immersion holes (3) at least include a plurality of basic hole positions (31) for printing to obtain basic tin-immersion points; The portions of the plurality of tin-immersion holes (3) whose diameters are larger than the diameters of the basic holes (31) are enlarged holes (32), and the diameter enlargement values ​​of the plurality of enlarged holes (32) are determined according to the specifications of the matching printed circuit pads; The basic hole position (31) is arranged on the basic platform position (21), and the enlarged hole position (32) is arranged on the matching elevated platform position (22).

4. A step steel mesh with controllable tin-immersion thickness according to any one of claims 1 to 3, characterized in that: The side walls of the tinning platform (2) are formed with landslides (23), and there is a smooth transition between the landslides (23) and the surface of the tinning platform (2), and there is a smooth transition between two adjacent landslides (23).

5. The step steel mesh with controllable tin-immersion thickness according to claim 4, characterized in that: A tin sinking tank (11) is centrally arranged on the printing plate (1), and the plurality of tin sinking platforms (2) and the plurality of tin sinking holes (3) are all located in the tin sinking tank (11), and the depth of the tin sinking tank (11) is greater than or equal to the highest height of the plurality of tin sinking platforms (2); The tin sinking tank (11) has material slopes (12) formed on both side walls facing the solder paste to be scraped and printed, and the side walls adjacent to the material slopes (12) are arranged vertically to limit the lateral flow of the solder paste, and the material slopes (12) are smoothly transitioned to the bottom of the tin sinking tank (11) and the surface of the printing plate (1), respectively.

6. The step steel mesh with controllable tin thickness according to claim 5, characterized in that: An anti-overflow frame (13) is provided on the printing plate (1), and the anti-overflow frame (13) is placed around the tin sink (11), and the distance between two opposite side walls of the anti-overflow frame (13) is equal to the distance between two vertical side walls of the tin sink (11), and the distance between the other two opposite side walls of the anti-overflow frame (13) is greater than the distance between the upper edges of the two material slopes (12).

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