Screen board, circuit board and electronic equipment
By designing mesh units with multi-directional airflow channels on the mesh board, the poor welding effect and pad structural strength problems are solved, and the assembly yield and pad stability are improved.
Patent Information
- Application Number
- CN202420241745.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-31
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2034-01-31
AI Technical Summary
The existing mesh board design leads to poor welding effect of electronic components, reducing assembly yield, and unreliable strength of the pad structure.
The first area of the design mesh plate has a plurality of mesh units, a first interval is provided between adjacent mesh units, a second interval is provided between adjacent mesh units in the mesh unit, and an extension of the first and second intervals. The direction is angled, forming a multi-directional airflow channel to avoid excessive dispersion of solder paste and ensure the strength of the pad structure.
It improves welding effect and assembly yield, reduces bubble rate and micro-short circuit defect rate, and enhances the stability and connection strength of the pad structure.
Smart Images
Figure CN222235135U_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of electronic equipment, and in particular to a stencil, a circuit board and electronic equipment. Background Art
[0002] With the continuous development of technology, more and more electronic components are soldered on circuit boards through Quad Flat No-leads Package (QFN), and the design of the stencil is one of the key factors affecting the assembly yield. The stencil design in the related art makes the soldering effect of electronic components poor, thereby reducing the assembly yield. Utility Model Content
[0003] In order to overcome the problems existing in the related art, the present disclosure provides a mesh board, a circuit board and an electronic device.
[0004] According to a first aspect of the present disclosure, a mesh plate is provided, the mesh plate having a first area, wherein a plurality of mesh units are arranged in the first area, a first interval is provided between two adjacent mesh units, the mesh unit comprises at least three first meshes, and in the same mesh unit, a second interval is provided between adjacent first meshes, the second intervals in the same mesh unit are separated from each other, and an extension direction of the first interval and an extension direction of the second interval are arranged at an angle.
[0005] In some embodiments of the present disclosure, the plurality of mesh units are arranged in an array, and an extension direction of the second interval is arranged at an angle to both a row direction and a column direction of the array.
[0006] In some embodiments of the present disclosure, in two adjacent mesh units located in the same row, at least one second interval of each mesh unit has a first end facing the other mesh unit, and a first connecting line of the first ends of the two mesh units is set at an angle to an extension direction of the second interval; and / or, in two adjacent mesh units located in the same column, at least one second interval of each mesh unit has a second end facing the other mesh unit, and a second connecting line of the second ends of the two mesh units is set at an angle to an extension direction of the second interval.
[0007] In some embodiments of the present disclosure, each mesh unit is shaped like a rectangular structure, the extension direction of the second interval is parallel to the first diagonal of the rectangular structure, and in one mesh unit, the at least three first meshes are arranged at intervals along the second diagonal direction of the rectangular structure.
[0008] In some embodiments of the present disclosure, the extension directions of the second intervals of the mesh units in the same row are parallel; and the extension directions of the second intervals of the mesh units in different rows are arranged at an angle.
[0009] In some embodiments of the present disclosure, the total area of the first meshes in the first region is 38% to 42% of the total area of the first region.
[0010] In some embodiments of the present disclosure, the mesh plate further has a second area, the second area is arranged around the periphery of the first area, and a plurality of second mesh holes are arranged at intervals along an extension direction of the second area.
[0011] In some embodiments of the present disclosure, the total area of the second meshes in the second region is 55% to 85% of the total area of the second region.
[0012] According to a second aspect of the present disclosure, a circuit board is provided, on which a solder pad printed by screen printing as described in the first aspect is disposed.
[0013] According to a third aspect of the present disclosure, an electronic device is provided, comprising the circuit board as described in the second aspect.
[0014] The technical solution provided by the embodiments of the present disclosure may have the following beneficial effects:
[0015] The mesh plate provided by the embodiment of the present disclosure has a plurality of mesh units arranged on the first area, a first interval is provided between two adjacent mesh units, and at the same time, the mesh unit includes at least three first meshes, and in the same mesh unit, a second interval is provided between adjacent first meshes, and the extension direction of the first interval and the extension direction of the second interval are arranged at an angle. Such a design can realize multi-directional airflow during the welding process, thereby effectively improving the welding effect and the assembly yield, and the second intervals located in the same mesh unit are separated from each other, which can ensure that the first meshes are not overly dispersed, thereby effectively ensuring the structural strength of the pad structure formed on the circuit board.
[0016] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0018] Figure 1 It is a structural schematic diagram of a circuit board in the related art;
[0019] Figure 2It is a structural schematic diagram of a mesh plate in the related art;
[0020] Figure 3 In the related art, Figure 2 Inspection diagram of a circuit board made of a stencil;
[0021] Figure 4 It is a structural schematic diagram of another stencil in the related art;
[0022] Figure 5 In the related art, Figure 4 Inspection diagram of a circuit board made of a stencil;
[0023] Figure 6 is a schematic structural diagram of a mesh panel according to an exemplary embodiment;
[0024] Figure 7 According to an exemplary embodiment, Figure 6 Inspection diagram of a circuit board made of a stencil.
[0025] In the figure:
[0026] 1-mesh; 11-first area; 111-mesh unit; 1111-first mesh; 1112-second interval; 1113-first end; 1114-first connection line; 1115-second end; 1116-second connection line; 112-first interval; 12-second area; 121-second mesh; 2-circuit board; 21-heat dissipation pad; 22-functional pad; 23-solder paste. DETAILED DESCRIPTION
[0027] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.
[0028] With the continuous development of technology, more and more electronic components are soldered on circuit boards through Quad Flat No-leads Package (QFN). It can be understood that QFN is a leadless package, which is square or rectangular. There is a large exposed pad in the center of the bottom of the package for heat conduction, and there are conductive pads around the periphery of the package for electrical connection. For example, Figure 1As shown, the QFN includes a circuit board 2 and pads arranged on the circuit board 2, the pads including a heat dissipation pad 21 located in the center for heat conduction, and a plurality of functional pads 22 surrounding the heat dissipation pad 21, and the electrical connection between the circuit board 2 and the electronic components is achieved through the functional pads 22.
[0029] The pad is formed by depositing solder paste on the circuit board 2 through the stencil 1. For example, the stencil 1 is provided with mesh holes for depositing solder paste. When the solder paste is deposited, the stencil 1 is demoulded. Therefore, the design of the stencil 1 is one of the key factors affecting the assembly yield. For example, the hole design of the heat dissipation pad 21 and the hole design of the functional pad 22 affect the balance of the solder paste deposition amount, which is closely related to the generation of welding defects, and welding defects affect the assembly yield.
[0030] Exemplarily, when the amount of solder paste deposited on the heat dissipation pad 21 is greater than the amount of solder paste deposited on the surrounding functional pads 22, the electronic component may be easily lifted up by the solder paste on the middle heat dissipation pad 21, thereby causing empty solder joints with the functional pads 22; or, during the soldering process, the solder paste on the heat dissipation pad 21 may be pressurized and overflow to the functional pad 22, thereby causing a short circuit on the functional pad 22; or, due to the excessive amount of solder paste on the heat dissipation pad 21, the electronic component may rotate at an angle due to the surface tension of the solder paste during the soldering process, thereby causing the solder paste connection of some functional pads 22 to cause a short circuit.
[0031] When the amount of solder paste deposited on the heat dissipation pad 21 is less than that on the surrounding functional pads 22, the solder paste on the functional pads 22 may be connected due to pressure during the soldering process, causing a short circuit.
[0032] In addition, due to the inappropriate design of the stencil 1, the gas generated by the solder paste 23 of the heat dissipation pad 21 during the welding process cannot be discharged smoothly, and the accumulated gas generates bubbles, which in turn causes internal pores, pinholes and other solder voids in the heat dissipation pad 21. When the voids are too large, not only will the heat dissipation requirements not be met, but also insufficient electrical or mechanical connections will be caused. On the other hand, during the welding process, the force released by the gas generated on the heat dissipation pad 21 will sputter a small amount of solder paste between two adjacent functional pads 22, and then the sputtered solder paste will cause a micro-bridge short circuit to be formed, reducing the assembly yield.
[0033] Therefore, the design of the stencil 1 not only needs to consider the balance between the solder paste deposition amount of the heat dissipation pad 21 and the solder paste deposition amount of the functional pad 22, but also needs to form a suitable gas channel to reduce the bubble rate, which is beneficial to the heat dissipation of electronic components, as well as reduce micro-connection phenomena and improve assembly yield.
[0034] Based on this, in the related art, the mesh plate 1 separates the area corresponding to the heat dissipation pad 21 to form a gas diffusion channel. For example, Figure 2 As shown, the mesh plate 1 is divided into a first area 11 and a second area 12, and the second area 12 surrounds the first area 11. A plurality of mesh units 111 are arranged on the first area 11, and a first interval 112 is provided between two adjacent mesh units 111. Two first meshes 1111 are provided in each mesh unit 111, and the total area of the first meshes 1111 is 53.5% of the total area of the first area 11. A second interval 1112 is provided between two first meshes 1111 in the same mesh unit 111. Along the extension direction of the second area 12, a plurality of second meshes 121 are arranged at intervals, and the total area of the second meshes 121 is 58% of the total area of the second area 12.
[0035] The first interval 112 and the second interval 1112 provide two mutually perpendicular airflow channels for the gas generated during the welding process, and the gas can flow out along the first interval 112 and the second interval 1112. The circuit board 2 is printed with solder paste through the screen 1, and the solder paste 23 deposited by the first mesh 1111 forms a heat dissipation pad 21, and the solder paste deposited by the second mesh 121 forms a functional pad 22. The circuit board 2 after welding is tested by X-ray detection, for example, to detect the assembly yield, such as Figure 3 As shown, although the bubble rate can be improved to a certain extent, there are still a large number of bubbles, and the size of the bubbles is uneven, which reduces the welding effect. At the same time, there will be a micro short circuit defect rate of about 0.17% during the welding process.
[0036] In this regard, the related art further optimizes the screen 1, for example, Figure 4 As shown, the mesh plate 1 is divided into a first area 11 and a second area 12, and the second area 12 surrounds the first area 11. A plurality of mesh units 111 are arranged on the first area 11, and a first interval 112 is provided between two adjacent mesh units 111. The mesh unit 111 is rectangular, and each mesh unit 111 is provided with a first mesh 1111 at the four corners, and the total area of the first mesh 1111 is 35% of the total area of the first area 11. In the same mesh unit 111, four first meshes 1111 form two mutually perpendicular second intervals 1112. Along the extension direction of the second area 12, a plurality of second meshes 121 are arranged at intervals, and the total area of the second meshes 121 is 58% of the total area of the second area 12.
[0037] Each mesh unit 111 provides two mutually perpendicular air flow channels for the gas generated during the welding process, and at the same time, the gas can also flow out from the first interval 112 between adjacent mesh units 111. The circuit board 2 is printed with solder paste through this stencil 1, and the solder paste deposited by the first mesh 1111 forms a heat dissipation pad 21, and the solder paste deposited by the second mesh 121 forms a functional pad 22. The circuit board 2 after welding is tested by X-ray detection, for example, to detect the assembly yield, such as Figure 5 As shown, during the welding process, some solder paste 23 will still splash onto the functional pad 22 to cause micro short circuits, and the defect rate of micro short circuits is 0.09%. At the same time, the size of the bubbles generated is also uneven, which will also reduce the welding effect.
[0038] In addition, there is a mesh in the related art, which can improve the welding effect, but will cause the structural strength of the pad structure formed on the circuit board to be unreliable. The structure of the mesh is unreliable. Exemplarily, the mesh 1 is divided into a first area and a second area, and the second area surrounds the first area. A plurality of mesh units are arranged on the first area, and a first interval is provided between two adjacent mesh units. Each mesh unit is provided with four first mesh holes, and the four first mesh holes form two mutually intersecting second intervals, wherein the mesh unit is rectangular, one second interval is located on one diagonal line, and the other second interval is located on the other diagonal line. Since the two second intervals in the same mesh unit are intersecting and connected with each other, the four first mesh holes are overly dispersed, thereby causing the pad structure formed on the circuit board to be dispersed, thereby reducing the structural strength of the pad structure.
[0039] In summary, the stencil design in the related art still results in poor welding effect of electronic components, thereby reducing assembly yield.
[0040] In order to solve the above technical problems, the present disclosure provides a mesh plate, wherein a plurality of mesh units are arranged on a first area, a first interval is provided between two adjacent mesh units, and at the same time, the mesh unit includes at least three first meshes, and in the same mesh unit, a second interval is provided between adjacent first meshes, and the extension direction of the first interval and the extension direction of the second interval are arranged at an angle. With such a design, multi-directional airflow can be achieved during the welding process, thereby effectively improving the welding effect and the assembly yield, and the second intervals located in the same mesh unit are separated from each other, which can ensure that the first meshes are not overly dispersed, thereby effectively ensuring the structural strength of the pad structure formed on the circuit board.
[0041] An exemplary embodiment of the present disclosure provides a screen such as Figure 6As shown, the stencil 1 has a first area 11, and the first area 11 is provided with a plurality of mesh units 111, and a first interval 112 is provided between two adjacent mesh units 111. The mesh unit 111 includes at least three first meshes 1111. For example, the mesh unit 111 may be provided with only three first meshes 1111, or more than three first meshes 1111 may be provided. In the same mesh unit 111, there is a second interval 1112 between adjacent first meshes 1111, and each second interval 1112 in the same mesh unit 111 is separated from each other. For example, in the same mesh unit 111, each second interval 1112 is separated from each other, that is, not connected to each other, and both ends of each second interval 1112 may be connected to the first interval 112 opposite thereto. When solder paste is printed through the stencil 1 in this embodiment, the solder paste is deposited from each first mesh 1111, and an air flow channel is formed under the action of the first interval 112 and the second interval 1112. During welding, gas may flow out along the first gap 112 and the second gap 1112 .
[0042] The extension direction of the first interval 112 and the extension direction of the second interval 1112 are set at an angle, thereby providing airflow channels in at least three directions for the gas, which is more conducive to the release of the gas and avoids the airflow from gathering due to poor circulation, thereby effectively improving the smoothness of gas discharge. In this way, on the one hand, it can effectively reduce the bubble rate, improve the welding effect, avoid the generation of solder voids, and thus improve the connection stability between the electronic component and the circuit board 2. On the other hand, it can also effectively avoid the sputtering of solder paste due to gas release, thereby effectively reducing the defective rate of micro short circuits. For example, Figure 7 The inspection diagram of the soldered circuit board 2 by X-ray inspection means is shown. After soldering, the size and distribution of the bubbles generated are uniform, which can effectively improve the soldering effect, thereby improving the heat dissipation effect of the electronic components, and further improving the connection stability between the electronic components and the circuit board 2. At the same time, the defective rate of micro short circuits can be reduced from 0.09% to almost nothing, thereby effectively improving the assembly yield.
[0043] Such a design can achieve multi-directional airflow during the welding process, thereby effectively improving the welding effect and the assembly yield. The second intervals 1112 located in the same mesh unit 111 are separated from each other, which can ensure that the first mesh 1111 is not overly dispersed, thereby effectively ensuring the structural strength of the mesh plate 1.
[0044] In one embodiment, in combination Figure 6 , the plurality of mesh units 111 are arranged in an array, and the extension direction of the second interval 1112 is parallel to the row direction of the array (eg Figure 6 The x-direction shown in Figure 6The y direction shown in the figure is arranged at an angle, and the angle is, for example, 45°. Such an arrangement is conducive to achieving airflow in more directions during the welding process, thereby further improving the welding effect.
[0045] In one embodiment, in combination Figure 6 In two adjacent mesh units 111 in the same row, at least one second interval 1112 of each mesh unit 111 has a first end 1113 facing another mesh unit 111, and a first connecting line 1114 of the first ends 1113 of the two mesh units 111 is arranged at an angle to the extension direction of the second interval 1112. Such a design can further ensure that airflow channels in more directions are realized during the welding process, thereby improving the welding effect.
[0046] In another embodiment, in combination Figure 6 In two adjacent mesh units 111 in the same column, at least one second interval 1112 of each mesh unit 111 has a second end 1115 facing another mesh unit 111, and a second connecting line 1116 of the second ends 1115 of the two mesh units 111 is arranged at an angle to the extension direction of the second interval 1112. In this way, it is also possible to further ensure that airflow channels in more directions are realized during the welding process, thereby improving the welding effect.
[0047] In another embodiment, in combination Figure 6 , in two adjacent mesh units 111 located in the same row, at least one second interval 1112 of each mesh unit 111 has a first end 1113 facing the other mesh unit 111, and a first connecting line 1114 of the first ends 1113 of the two mesh units 111 is set at an angle to the extension direction of the second interval 1112. At the same time, in two adjacent mesh units 111 located in the same column, at least one second interval 1112 of each mesh unit 111 has a second end 1115 facing the other mesh unit 111, and a second connecting line 1116 of the second ends 1115 of the two mesh units 111 is set at an angle to the extension direction of the second interval 1112. Such a setting form is adopted to further ensure that more airflow channels are realized in the welding process, which is more conducive to the release of gas and avoids the aggregation of airflow due to poor circulation, thereby effectively improving the fluency of gas discharge and further improving the welding effect.
[0048] In one embodiment, in combination Figure 6Each mesh unit 111 is in the shape of a rectangular structure, having a first diagonal and a second diagonal intersecting each other. The extension direction of the second interval 1112 is parallel to the first diagonal of the rectangular structure, and at least three first meshes 1111 in the same mesh unit 111 are arranged in a spaced manner along the second diagonal direction of the rectangular structure. Such a design makes the extension direction of each second interval 1112 uniform, thereby facilitating the processing of the screen plate 1.
[0049] In one embodiment, the extension directions of the second intervals 1112 of the mesh units 111 in the same row are parallel, while the extension directions of the second intervals 1112 of the mesh units 111 in different rows are arranged at an angle, which may be 45°, for example. Such a design facilitates the processing of the mesh plate 1 and is conducive to achieving airflow in more directions during the welding process, thereby further improving the welding effect.
[0050] In one embodiment, the total area of the first meshes 1111 of the first region 11 is 38% to 42% of the total area of the first region 11, for example, 40% of the total area of the first region 11. With such a configuration, the problem of empty soldering and short circuit caused by excessive deposition of solder paste through the first meshes 1111 is avoided, thereby further improving the soldering effect and the assembly yield.
[0051] In one embodiment, in combination Figure 6 The mesh plate 1 also has a second area 12, which is arranged around the periphery of the first area 11, and a plurality of second meshes 121 are arranged at intervals along the extension direction of the second area 12. For example, the pad formed by the solder paste deposited from the first mesh 1111 is used for heat dissipation of electronic components, and the pad formed by the solder paste deposited from the second mesh 121 is used for electrical connection between the electronic components and the circuit board 2. With such a design, on the one hand, an air flow channel can be formed between adjacent second meshes 121, and during the welding process, the gas can flow out along the air flow channel to avoid the air flow from gathering due to poor circulation, thereby effectively improving the smoothness of gas discharge, improving the welding effect, and effectively reducing the defective rate of micro short circuits. On the other hand, by arranging the plurality of second meshes 121 at intervals, the short circuit caused by the connection of the solder paste under pressure during the welding process is avoided, thereby further reducing the defective rate of micro short circuits and improving the assembly yield.
[0052] In one embodiment, the total area of the second meshes 121 of the second region 12 is 55% to 85% of the total area of the second region 12, for example, 70% of the total area of the second region 12. With such a configuration, the problem of empty soldering and short circuit caused by the imbalance between the amount of solder paste deposited through the second meshes 121 and the amount of solder paste deposited from the first meshes 1111 is avoided, thereby further improving the soldering effect and the soldering yield.
[0053] An exemplary embodiment of the present disclosure provides a circuit board 2, on which a pad printed by the stencil 1 as described above is provided. Exemplarily, solder paste is printed by the stencil 1, and the solder paste deposited from the first mesh 1111 forms a heat dissipation pad 21 on the circuit board 2, and the heat dissipation pad 21 is used for heat dissipation of electronic components, and the solder paste deposited from the second mesh 121 forms a functional pad 22 on the circuit board 2, and the functional pad 22 is used for electrical connection between the electronic component and the circuit board 2.
[0054] Combination Figure 6 The above-mentioned stencil 1 includes a stencil 1 having a first area 11, the first area 11 is provided with a plurality of mesh units 111, and a first interval 112 is provided between two adjacent mesh units 111. The mesh unit 111 includes at least three first meshes 1111. In the same mesh unit 111, a second interval 1112 is provided between adjacent first meshes 1111, and each second interval 1112 located in the same mesh unit 111 is separated from each other. When solder paste is printed through the stencil 1 in this embodiment, the solder paste is deposited from each first mesh 1111, and an air flow channel is formed under the action of the first interval 112 and the second interval 1112. During the welding process, the gas can flow out along the first interval 112 and the second interval 1112.
[0055] The extension direction of the first interval 112 and the extension direction of the second interval 1112 are set at an angle, thereby providing airflow channels in at least three directions for the gas, which is more conducive to the release of the gas and avoids the airflow from gathering due to poor circulation, thereby effectively improving the smoothness of gas discharge. In this way, on the one hand, it can effectively reduce the bubble rate, improve the welding effect, avoid the generation of solder voids, and thus improve the connection stability between the electronic component and the circuit board 2. On the other hand, it can also effectively avoid the sputtering of solder paste due to gas release, thereby effectively reducing the defective rate of micro short circuits. For example, Figure 7 The inspection diagram of the soldered circuit board 2 by X-ray inspection means is shown. After soldering, the size and distribution of the bubbles generated are uniform, which can effectively improve the soldering effect, thereby improving the heat dissipation effect of the electronic components, and further improving the connection stability between the electronic components and the circuit board 2. At the same time, the defective rate of micro short circuits can be reduced from 0.09% to almost nothing, thereby effectively improving the assembly yield.
[0056] In this embodiment, printing is performed by the stencil 1 as described above to form solder pads on the circuit board 2, which can achieve multi-directional airflow during the welding process, thereby effectively improving the welding effect and the assembly yield. The second intervals 1112 located in the same mesh unit 111 are separated from each other, which can ensure that the first mesh 1111 is not excessively dispersed, thereby effectively ensuring the structural strength of the stencil 1.
[0057] An exemplary embodiment of the present disclosure provides an electronic device, which may be, for example, a mobile phone, a tablet computer, a laptop computer, a PDA, an in-vehicle electronic device, a wearable device, an ultra-mobile personal computer (UMPC), a netbook, or a personal digital assistant (PDA), etc., and may also be a non-mobile device such as a personal computer (PC), a television (TV), a teller machine, or a self-service machine.
[0058] The electronic device includes the circuit board 2 as described above. The circuit board 2 is provided with pads printed by the screen 1 as described above, combined with Figure 6 The mesh plate 1 is provided with a plurality of mesh units 111 on the first area 11, and a first interval 112 is provided between two adjacent mesh units 111. At the same time, the mesh unit 111 includes at least three first meshes 1111. In the same mesh unit 111, a second interval 1112 is provided between adjacent first meshes 1111, and the extension direction of the first interval 112 and the extension direction of the second interval 1112 are arranged at an angle. Such a design can realize multi-directional airflow during the welding process, thereby effectively improving the welding effect and the assembly yield. The second intervals 1112 located in the same mesh unit 111 are separated from each other, which can ensure that the first meshes 1111 are not too dispersed, thereby effectively ensuring the structural strength of the mesh plate 1.
[0059] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.
[0060] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.
Claims
1. A screen, characterized in that: The mesh plate has a first area, and a plurality of mesh units are arranged in the first area. A first interval is provided between two adjacent mesh units. The mesh unit includes at least three first meshes. In the same mesh unit, a second interval is provided between adjacent first meshes. The second intervals in the same mesh unit are separated from each other, and an extension direction of the first interval and an extension direction of the second interval are arranged at an angle.
2. The screen according to claim 1, characterized in that: The plurality of mesh units are arranged in an array, and an extension direction of the second interval forms an angle with both a row direction and a column direction of the array.
3. The screen plate according to claim 2, characterized in that: In two adjacent mesh units located in the same row, at least one second interval of each mesh unit has a first end facing the other mesh unit, and a first connecting line of the first ends of the two mesh units is arranged at an angle to an extension direction of the second interval; and / or, In two adjacent mesh units in the same column, at least one second interval of each mesh unit has a second end facing the other mesh unit, and a second connecting line of the second ends of the two mesh units is arranged at an angle to an extension direction of the second interval.
4. The screen plate according to claim 1, characterized in that: Each mesh unit is in the shape of a rectangular structure, the extension direction of the second interval is parallel to the first diagonal of the rectangular structure, and in one mesh unit, the at least three first meshes are arranged at intervals along the second diagonal direction of the rectangular structure.
5. The screen plate according to claim 2, characterized in that: The extending directions of the second intervals of the mesh units in the same row are parallel; The extension directions of the second intervals of the mesh units in different rows are arranged at an angle.
6. The screen plate according to any one of claims 1 to 5, characterized in that: The total area of the first meshes in the first region is 38% to 42% of the total area of the first region.
7. The screen plate according to any one of claims 1 to 5, characterized in that: The mesh plate further has a second area, which is arranged around the outer periphery of the first area. A plurality of second mesh holes are arranged at intervals along the extending direction of the second area.
8. The screen plate according to claim 7, characterized in that: The total area of the second meshes in the second region is 55% to 85% of the total area of the second region.
9. A circuit board, characterized in that: The circuit board is provided with solder pads printed by screen printing according to any one of claims 1 to 8.
10. An electronic device, characterized in that: The electronic device comprises the circuit board as claimed in claim 9.