Steel mesh structure, solder paste printing device and circuit board production system
By designing the matching relationship between the mesh area and the pad area of the steel mesh structure, the solder paste printing volume is reduced and the heat dissipation efficiency of the three-end FUSE is reduced, which solves the problem of difficulty in fuse and welding position offset in the prior art, and improves the fuse reliability.
Patent Information
- Application Number
- CN202420855169.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-23
- Publication Date
- 2025-04-15
- Estimated Expiration
- 2034-04-23
AI Technical Summary
The size of the steel mesh structure window opening in the prior art is the same as the size of the solder paste, which leads to a large amount of solder paste printing, which in turn improves the heat dissipation efficiency of the three-end FUSE, which is difficult to fuse, and may lead to a shift in the welding position, affecting the reliability of fuse.
A steel mesh structure is designed, with the area of the first mesh and the third mesh holes being S1, the area of the pad being S2, and the value of S1/S2 is 0.5-0.64. The outer periphery of the mesh shrinks to the outer periphery of the pad, reducing the amount of solder paste printing, reducing the heat dissipation efficiency, and promoting the fuse of the three-end FUSE.
By reducing the printing volume of solder paste, the heat dissipation efficiency of the three-end FUSE is reduced, making it easier to fuse, improves fuse reliability, and prevents welding position deviation to ensure effective fuse.
Smart Images
Figure CN222764063U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of solder paste printing auxiliary tools, in particular to a steel mesh structure, a solder paste printing device and a circuit board production system. Background Art
[0002] The three-terminal FUSE is an electronic component for protecting circuits. It can effectively limit short-circuit current and protect the power supply circuit and load. When a short circuit or a current close to the short-circuit current occurs in the circuit, the three-terminal FUSE can stably cut off the power supply, prevent damage to certain devices or the power supply system in the circuit, and limit the damage to the smallest possible area.
[0003] The three pins of the three-terminal FUSE are respectively welded to the three corresponding pads on the circuit board. The voltage fusing of the three-terminal FUSE relies on the rapid heating of the heating end to fuse. When the three-terminal FUSE is used in a rapid heat dissipation environment, it will be difficult to fuse. When the three-terminal FUSE is blown, the main parts of its heat dissipation are pins 1 and 3. The window size of the steel mesh structure in the prior art is the same as the size of the pad, so that a sufficient amount of solder paste can be printed on the pad during the solder paste printing stage to ensure the welding firmness. This method results in a large amount of solder paste printed on the pad, resulting in an increase in the heat dissipation efficiency at pins 1 and 3 of the three-terminal FUSE, which is not conducive to the fusing of the three-terminal FUSE; and the solder paste printed on the pad has a certain fluidity during reflow soldering. The large amount of solder paste enhances its fluidity. When welding the three-terminal FUSE, the welding position is prone to offset, resulting in inconsistent heat dissipation environments of pins 1 and 3 of the three-terminal FUSE, which in turn leads to poor fusing of the three-terminal FUSE. Utility Model Content
[0004] In view of this, the utility model provides a steel mesh structure, a solder paste printing device and a circuit board production system to solve the problem in the prior art that the window size of the steel mesh structure is the same as the pad size, resulting in a large amount of printed solder paste, which in turn increases the difficulty of blowing the three-terminal FUSE and causes poor blowing.
[0005] In a first aspect, the utility model provides a steel mesh structure, comprising:
[0006] Support frame;
[0007] A mesh plate is arranged on the inner side of the supporting frame; a first mesh hole, a second mesh hole and a third mesh hole are provided on the mesh plate, wherein the relative positions of the first mesh hole, the second mesh hole and the third mesh hole are respectively determined according to the pad positions of the three pins of the three-terminal FUSE, the first mesh hole corresponds to the one-pin pad of the three-terminal FUSE, the third mesh hole corresponds to the three-pin pad of the three-terminal FUSE, the shape of the first mesh hole is adapted to the shape of the one-pin pad, and the shape of the third mesh hole is adapted to the shape of the three-pin pad; the areas of the first mesh hole and the third mesh hole are both S1, the areas of the one-pin pad and the three-pin pad are both S2, the value of S1 / S2 is 0.5-0.64, the outer periphery of the first mesh hole is inwardly contracted to the outer periphery of the one-pin pad, and the outer periphery of the third mesh hole is inwardly contracted to the outer periphery of the three-pin pad.
[0008] Beneficial effect: In the steel mesh structure of this structure, the area of the first mesh and the third mesh are both S1, the area of the one-leg pad and the three-leg pad are both S2, the value of S1 / S2 is 0.5-0.64, the periphery of the first mesh is inwardly contracted to the periphery of the one-leg pad, and the periphery of the third mesh is inwardly contracted to the periphery of the three-leg pad. The first mesh and the third mesh can reduce the amount of solder paste printed on the pad by reducing the window area, so as to reduce the solder paste area on the one-leg pad and the three-leg pad of the three-terminal FUSE, reduce the heat dissipation efficiency at the one-leg pad and the three-leg pad, and facilitate the heating end of the three-terminal FUSE to heat up and fuse, making the three-terminal FUSE easier to fuse, and improving the reliability of the three-terminal FUSE fuse. At the same time, after the window area of the first mesh and the third mesh is reduced, the amount of solder paste printed on the one-leg pad and the three-leg pad is reduced, which can reduce the fluidity of the solder paste during reflow soldering, thereby effectively preventing the welding position from shifting, ensuring the effective fuse of the three-terminal FUSE, and avoiding incomplete fuse.
[0009] In an optional implementation, the one-foot pad is rectangular, and the first mesh is rectangular.
[0010] In an optional embodiment, the length of the one-foot pad is L1, the width of the one-foot pad is W1, and the distance d1 between any hole wall at both ends of the first mesh in the length direction and the wide side of the adjacent one-foot pad is 0.2L1-0.25L1;
[0011] The distance d2 between any one hole wall at both ends of the first mesh in the width direction and the long side of the adjacent one-foot pad is 0.2W1-0.25W1.
[0012] Beneficial effect: The distance between the two hole walls in the length direction of the first mesh and the two wide sides of the one-foot pad is the same, and the distance between the two hole walls in the width direction of the first mesh and the two long sides of the one-foot pad is the same, that is, the first mesh is centered on the one-foot pad, and the solder paste is in the middle of the pad after printing, which is conducive to ensuring the welding effect. At the same time, the spacing between the hole wall of the first mesh and the four sides of the one-foot pad satisfies d1 of 0.2L1-0.25L1, d2 of 0.2W1-0.25W1, and the spacing between the first mesh and the four sides of the one-foot pad is moderate, which can ensure the heat dissipation effect, prevent the three-terminal FUSE from shifting during welding, and ensure the welding firmness.
[0013] In an optional embodiment, the distance d1 between any hole wall at both ends of the first mesh in the length direction and the wide side of the adjacent one-foot pad is 0.2L1;
[0014] The distance d2 between any hole wall at both ends of the first mesh in the width direction and the long side of the adjacent one-foot pad is 0.2W1.
[0015] In an optional implementation, the tripod pad is rectangular, and the third mesh is rectangular.
[0016] In an optional embodiment, the length of the tripod pad is L2, the width of the tripod pad is W2, and the distance d3 between any one hole wall at both ends of the third mesh in the length direction and the wide side of the adjacent tripod pad is 0.2L2-0.25L2;
[0017] The distance d4 between any one hole wall at both ends of the third mesh in the width direction and the long side of the adjacent tripod pad is 0.2W2-0.25W2.
[0018] Beneficial effect: The distance between the two hole walls in the length direction of the third mesh and the two wide sides of the tripod pad is the same, and the distance between the two hole walls in the width direction of the third mesh and the two long sides of the tripod pad is the same, that is, the third mesh is centrally attached to the upper part of the tripod pad, and the solder paste is in the middle of the tripod pad after printing, which is conducive to ensuring the welding effect. At the same time, the spacing between the hole wall of the third mesh and the four sides of the tripod pad satisfies d3 of 0.2L2-0.25L2, d4 of 0.2W2-0.25W2, and the spacing between the third mesh and the four sides of the tripod pad is moderate, which can ensure the heat dissipation effect, prevent the three-terminal FUSE from shifting during welding, and ensure the welding firmness.
[0019] In an optional embodiment, the distance d3 between any one hole wall at both ends of the third mesh in the length direction and the wide side of the adjacent tripod pad is 0.2L2;
[0020] The distance d4 between any one hole wall at both ends of the third mesh in the width direction and the long side of the adjacent tripod pad is 0.2W2.
[0021] In an optional implementation, the second mesh corresponds to a second-pin pad of a three-terminal FUSE, and an area of the second mesh is the same as an area of the second-pin pad.
[0022] In a second aspect, the utility model further provides a solder paste printing device, comprising the steel mesh structure and a placement table as described in any one of the above, wherein the steel mesh structure is located on the upper side of the placement table, and the placement table is suitable for placing a circuit board.
[0023] In a third aspect, the utility model further provides a circuit board production system, comprising the above-mentioned solder paste printing device and a circuit board, wherein the circuit board is placed on the placement table. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0025] Figure 1 A top view of a steel mesh structure according to an embodiment of the utility model;
[0026] Figure 2 A top view of a steel mesh structure according to an embodiment of the utility model, in which mesh holes and pads are attached to the pads of a circuit board;
[0027] Figure 3 This is a schematic diagram of the three-terminal FUSE pad.
[0028] Description of reference numerals:
[0029] 1. Support frame; 2. Mesh plate; 201. First mesh hole; 202. Second mesh hole; 203. Third mesh hole; 3. One-pin soldering pad; 4. Two-pin soldering pad; 5. Three-pin soldering pad. DETAILED DESCRIPTION
[0030] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.
[0031] Combine the following Figures 1 to 3 , describing an embodiment of the utility model.
[0032] According to an embodiment of the present utility model, on the one hand, a steel mesh structure is provided, such as Figure 1 As shown, it includes a support frame 1 and a mesh plate 2. The mesh plate 2 is arranged on the inner side of the support frame 1; the mesh plate 2 is provided with a first mesh hole 201, a second mesh hole 202 and a third mesh hole 203, wherein the relative positions of the first mesh hole 201, the second mesh hole 202 and the third mesh hole 203 are determined according to the pad positions of the three pins of the three-terminal FUSE, respectively, with reference to Figure 1 The schematic structure of the present invention is shown in FIG. 1 , wherein three meshes are respectively distributed on three sides of a rectangular structure, and the first mesh 201 and the second mesh 202 are opposite to each other and are arranged at intervals. The first mesh 201, the second mesh 202 and the third mesh 203 are suitable for being attached to the pads of three pins of the three-terminal FUSE. The first mesh 201 corresponds to the one-pin pad 3 of the three-terminal FUSE, and the third mesh 203 corresponds to the three-pin pad 5 of the three-terminal FUSE. The shape of the first mesh 201 is adapted to the shape of the one-pin pad 3, and the shape of the third mesh 203 is adapted to the shape of the three-pin pad 5. The areas of the first mesh 201 and the third mesh 203 are both S1, and the areas of the one-pin pad 3 and the three-pin pad 5 are both S2. The value of S1 / S2 is 0.5-0.64. The outer periphery of the first mesh 201 is retracted inside the outer periphery of the one-pin pad 3, and the outer periphery of the third mesh 203 is retracted inside the outer periphery of the three-pin pad 5.
[0033] In the steel mesh structure of this structure, the area of the first mesh 201 and the third mesh 203 are both S1, the area of the one-leg pad 3 and the three-leg pad 5 are both S2, the value of S1 / S2 is 0.5-0.64, the periphery of the first mesh 201 is inwardly contracted to the periphery of the one-leg pad 3, and the periphery of the third mesh 203 is inwardly contracted to the periphery of the three-leg pad 5. The first mesh 201 and the third mesh 203 can reduce the amount of solder paste printed on the pad by reducing the window area, so as to reduce the solder paste area on the one-leg pad 3 and the three-leg pad 5 of the three-terminal FUSE, reduce the heat dissipation efficiency at the one-leg pad 3 and the three-leg pad 5, facilitate the heating end of the three-terminal FUSE to heat up and fuse, make the three-terminal FUSE more easily fuse, and improve the reliability of the three-terminal FUSE fuse. At the same time, after the window areas of the first mesh 201 and the third mesh 203 are reduced, the amount of solder paste printed on the one-pin solder pad 3 and the three-pin solder pad 5 is reduced, which can reduce the fluidity of the solder paste during reflow soldering, thereby effectively preventing the welding position from shifting, ensuring that the three-terminal FUSE is effectively blown, and avoiding incomplete blowing.
[0034] The shape of the first mesh 201 is adapted to the shape of the one-pin pad 3, and the shape of the third mesh 203 is adapted to the shape of the three-pin pad 5. The outer periphery of the first mesh 201 is inwardly contracted to the outer periphery of the one-pin pad 3, and the outer periphery of the third mesh 203 is inwardly contracted to the outer periphery of the three-pin pad 5, so that the solder paste can be printed through the mesh to the middle area of the pad to ensure the soldering firmness. The value of S1 / S2 is 0.5-0.64, and the opening area of the first mesh 201 and the third mesh 203 is moderate, so as to avoid too small an opening area, resulting in too little solder paste printed on the pad and unable to ensure the soldering firmness, and at the same time, it can prevent too large an opening area from resulting in too much solder paste printed on the pad, which affects the fusing of the three-terminal FUSE.
[0035] Optionally, in one embodiment, Figures 1 to 3 As shown, the one-foot pad 3 is rectangular, the first mesh hole 201 is rectangular, the steel mesh structure is attached to the circuit board, and the four hole walls of the first mesh hole 201 are respectively arranged at a certain distance from the four sides of the one-foot pad 3.
[0036] In other embodiments, the one-foot pad 3 may also be circular or elliptical, and the shape of the first mesh 201 is the same as the shape of the one-foot pad 3 .
[0037] Optionally, in one embodiment, Figure 2As shown, the length of the one-leg soldering pad 3 is L1, the width of the one-leg soldering pad 3 is W1, and the spacing d1 between the distance between any one of the hole walls at the two ends of the length direction of the first mesh 201 and the wide side of the one-leg soldering pad 3 adjacent to it is 0.2L1-0.25L1; the spacing d2 between the distance between any one of the hole walls at the two ends of the width direction of the first mesh 201 and the long side of the one-leg soldering pad 3 adjacent to it is 0.2W1-0.25W1, the distance between the two hole walls in the length direction of the first mesh 201 and the two wide sides of the one-leg soldering pad 3 is the same, and the distance between the two hole walls in the width direction of the first mesh 201 and the two long sides of the one-leg soldering pad 3 is the same, that is, the first mesh 201 is centered on the one-leg soldering pad 3, and after printing the solder paste, the solder paste is in the middle position of the soldering pad, which is beneficial to ensuring the welding effect. At the same time, the spacing between the hole wall of the first mesh 201 and the four sides of the one-foot pad 3 satisfies d1 of 0.2L1-0.25L1, d2 of 0.2W1-0.25W1. The spacing between the four sides of the first mesh 201 and the one-foot pad 3 is moderate, which can not only ensure the heat dissipation effect and prevent the three-terminal FUSE from shifting during welding, but also ensure the welding firmness.
[0038] Optionally, in this embodiment, the spacing d1 between the distance between any one of the hole walls at both ends of the length direction of the first mesh 201 and the wide side of the adjacent one-foot pad 3 is 0.2L1; the spacing d2 between the distance between any one of the hole walls at both ends of the width direction of the first mesh 201 and the long side of the adjacent one-foot pad 3 is 0.2W1, which can further optimize the spacing between the four sides of the first mesh 201 and the one-foot pad 3, further ensure the heat dissipation effect at the one-foot pad 3, effectively prevent the three-terminal FUSE from offset during welding, and improve the welding firmness at the one-foot pad 3.
[0039] Optionally, in one embodiment, Figure 1 and Figure 2 As shown, the tripod pad 5 is rectangular, and the third mesh hole 203 is rectangular. The steel mesh structure is attached to the circuit board, and the four hole walls of the third mesh hole 203 are respectively arranged at a certain distance from the four sides of the tripod pad 5.
[0040] In other embodiments, the three-pin pad 5 may also be circular or elliptical, and the shape of the third mesh 203 is the same as that of the single-pin pad 3 .
[0041] like Figure 2As shown, in one embodiment, the length of the tripod pad 5 is L2, the width of the tripod pad 5 is W2, the distance d3 between any one of the two ends of the third mesh 203 in the length direction and the wide side of the adjacent tripod pad 5 is 0.2L2-0.25L2; the distance d4 between any one of the two ends of the third mesh 203 in the width direction and the long side of the adjacent tripod pad 5 is 0.2W2-0.25W2. The distance between the two hole walls in the length direction of the third mesh 203 and the two wide sides of the tripod pad 5 is the same, and the distance between the two hole walls in the width direction of the third mesh 203 and the two long sides of the tripod pad 5 is the same, that is, the third mesh 203 is centered and attached to the upper part of the tripod pad 5, and after printing the solder paste, the solder paste is in the middle of the tripod pad 5, which is conducive to ensuring the welding effect. At the same time, the distance between the hole wall of the third mesh 203 and the four sides of the tripod pad 5 satisfies d3 of 0.2L2-0.25L2, d4 of 0.2W2-0.25W2, and the distance between the four sides of the third mesh 203 and the tripod pad 5 is moderate, which can not only ensure the heat dissipation effect, prevent the three-terminal FUSE from shifting during welding, but also ensure the welding firmness.
[0042] Specifically, in this embodiment, the distance d3 between any one of the two ends of the third mesh 203 in the length direction and the wide side of the adjacent tripod pad 5 is 0.2L2; the distance d4 between any one of the two ends of the third mesh 203 in the width direction and the long side of the adjacent tripod pad 5 is 0.2W2. The distance between the third mesh 203 and the four sides of the tripod pad 5 can be further optimized to further ensure the heat dissipation effect at the tripod pad 5, effectively prevent the three-terminal FUSE from shifting during welding, and improve the welding firmness at the tripod pad 5.
[0043] like Figure 2 As shown, the second mesh 202 corresponds to the second pad 4 of the three-terminal FUSE, and the area of the second mesh 202 is the same as the area of the second pad 4. After the steel mesh structure is attached to the circuit board, the area of the second mesh 202 completely overlaps with the area of the second pad 4, and the solder paste is printed on the second pad 4 through the second mesh 202.
[0044] like Figure 2 and Figure 3As shown, optionally, in one embodiment, the first mesh 201 and the third mesh 203 have the same shape and size, the length of the first mesh 201 is 2.25mm, and the width of the first mesh 201 is 0.95mm; the length L3 of the second mesh 202 is 1.45mm, and the width W3 of the second mesh 202 is 0.75mm. The spacing between the first mesh 201 and the third mesh 203 is 1.6mm, the second mesh 202 is arranged on the upper part of the first mesh 201 and the third mesh 203, and the second mesh 202 is centrally arranged between the first mesh 201 and the third mesh 203. The spacing between the second mesh 202 and the first mesh 201 in the vertical direction is 0.25mm, and the spacing between the second mesh 202 and the first mesh 201 in the left-right direction is 0.07mm. The one-foot pad 3 and the three-foot pad 5 have the same shape and size.
[0045] According to an embodiment of the utility model, on the other hand, a solder paste printing device is also provided, comprising the above-mentioned steel mesh structure, a placement table and a scraper, wherein the steel mesh structure is located on the upper side of the placement table, and the placement table is suitable for placing a circuit board.
[0046] The circuit board is placed on the placement table, the steel mesh structure is lowered to fit above the circuit board, solder paste is applied, and the scraper is moved to evenly apply the solder paste to the surface of the steel mesh structure. The solder paste is applied to the one-pin solder pad 3, the two-pin solder pad 4 and the three-pin solder pad 5 through the first mesh 201, the second mesh 202 and the third mesh 203.
[0047] The solder paste printing device of this structure has a steel mesh structure on which the amount of solder paste printed on the pad can be reduced by reducing the window area of the first mesh 201 and the third mesh 203, so as to reduce the solder paste area on the one-leg solder pad 3 and the three-leg solder pad 5 of the three-terminal FUSE, reduce the heat dissipation efficiency at the one-leg solder pad 3 and the three-leg solder pad 5, make the three-terminal FUSE easier to blow, and improve the reliability of the three-terminal FUSE blowing. At the same time, the amount of solder paste printed on the one-leg solder pad 3 and the three-leg solder pad 5 is reduced, which can reduce the fluidity of the solder paste during reflow soldering, thereby effectively preventing the welding position from shifting and ensuring the effective blowing of the three-terminal FUSE.
[0048] According to an embodiment of the present invention, on the other hand, a circuit board production system is also provided, comprising the above-mentioned solder paste printing device and a circuit board, wherein the circuit board is placed on a placement table.
[0049] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.
Claims
1. A steel mesh structure, characterized in that: include: Support frame (1); A mesh plate (2) is arranged on the inner side of the support frame (1); the mesh plate (2) is provided with a first mesh hole (201), a second mesh hole (202) and a third mesh hole (203), wherein the relative positions of the first mesh hole (201), the second mesh hole (202) and the third mesh hole (203) are respectively determined according to the positions of the pads of the three pins of the three-terminal FUSE, the first mesh hole (201) corresponds to the pad (3) of one pin of the three-terminal FUSE, the third mesh hole (203) corresponds to the pad (5) of the three pins of the three-terminal FUSE, and ... third mesh hole (203) corresponds to the pad (5) of the three pins of the three-terminal FUSE. The shape of (201) is adapted to the shape of the one-pin solder pad (3), and the shape of the third mesh (203) is adapted to the shape of the three-pin solder pad (5); the areas of the first mesh (201) and the third mesh (203) are both S1, the areas of the one-pin solder pad (3) and the three-pin solder pad (5) are both S2, the value of S1 / S2 is 0.5-0.64, the outer periphery of the first mesh (201) is inwardly contracted to the outer periphery of the one-pin solder pad (3), and the outer periphery of the third mesh (203) is inwardly contracted to the outer periphery of the three-pin solder pad (5).
2. The steel mesh structure according to claim 1, characterized in that: The one-foot pad (3) is rectangular, and the first mesh hole (201) is rectangular.
3. The steel mesh structure according to claim 2, characterized in that: The length of the one-foot pad (3) is L1, the width of the one-foot pad (3) is W1, and the distance d1 between any hole wall at the two ends in the length direction of the first mesh (201) and the wide side of the adjacent one-foot pad (3) is 0.2L1-0.25L1; The distance d2 between the wall of any one of the two ends of the first mesh hole (201) in the width direction and the long side of the adjacent one-foot pad (3) is 0.2W1-0.25W1.
4. The steel mesh structure according to claim 3, characterized in that: The distance d1 between the wall of any one of the two ends of the first mesh hole (201) in the length direction and the wide side of the adjacent one-foot pad (3) is 0.2L1; The distance d2 between any one of the hole walls at the two ends in the width direction of the first mesh hole (201) and the long side of the adjacent one-foot pad (3) is 0.2W1.
5. The steel mesh structure according to any one of claims 1 to 4, characterized in that: The tripod pad (5) is rectangular, and the third mesh (203) is rectangular.
6. The steel mesh structure according to claim 5, characterized in that: The length of the tripod pad (5) is L2, the width of the tripod pad (5) is W2, and the distance d3 between any one of the hole walls at the two ends in the length direction of the third mesh (203) and the wide side of the adjacent tripod pad (5) is 0.2L2-0.25L2; The distance d4 between the wall of any one of the two ends of the third mesh hole (203) in the width direction and the long side of the adjacent tripod pad (5) is 0.2W2-0.25W2.
7. The steel mesh structure according to claim 6, characterized in that: The distance d3 between the wall of any one of the two ends of the third mesh hole (203) in the length direction and the wide side of the adjacent tripod pad (5) is 0.2L2; The distance d4 between any one of the hole walls at the two ends in the width direction of the third mesh hole (203) and the long side of the adjacent tripod pad (5) is 0.2W2.
8. The steel mesh structure according to any one of claims 1 to 4, characterized in that: The second mesh hole (202) corresponds to the two-pin pad (4) of the three-terminal FUSE, and the area of the second mesh hole (202) is the same as the area of the two-pin pad (4).
9. A solder paste printing device, characterized in that: It comprises the steel mesh structure and a placement table as described in any one of claims 1 to 8, wherein the steel mesh structure is located on the upper side of the placement table, and the placement table is suitable for placing a circuit board.
10. A circuit board production system, characterized in that: It comprises the solder paste printing device as claimed in claim 9 and a circuit board, wherein the circuit board is placed on the placement table.