PCB structure capable of shielding external electromagnetic interference

Abstract

The utility model discloses a PCB structure capable of shielding external electromagnetic interference, which comprises a substrate, a jumper resistor and a mounting hole arranged on the substrate, the surface layer of the substrate is provided with a first copper sheet, the bottom layer of the substrate is provided with a second copper sheet, and the first copper sheet and the second copper sheet respectively cover the peripheral area of the mounting hole. The substrate is provided with a plurality of via holes surrounding the periphery of the mounting hole, the plurality of via holes are used for connecting the first copper sheet and the second copper sheet, one end of the jumper resistor is connected with the first copper sheet, and the other end of the jumper resistor is connected with a GND copper sheet in the substrate. When an external electromagnetic interference signal enters the PCB through the mounting hole, the bridging resistor can form impedance to isolate or weaken the electromagnetic interference signal, so that the influence of the electromagnetic interference signal on a circuit in the PCB is prevented, the external electromagnetic interference signal can be reduced, and the reliability of the PCB is improved. And electromagnetic interference signals entering the PCB through the mounting holes can be effectively reduced or isolated.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit boards, and more specifically to a PCB structure capable of shielding external electromagnetic interference. Background Art

[0002] Printed Circuit Board (PCB), also known as printed circuit board, is an important component of the physical support and signal transmission of electronic products. The mounting holes of printed circuit boards are an important part of electronic design. Most mounting holes on PCB boards are connected to the GND plane, so that the mounting holes themselves not only provide mechanical fixation, but also provide grounding as part of the electrical connection. Mounting holes are frequently used on PCB boards. Their main function is to fix the PCB circuit board. In the finished PCB board, screws and gaskets are used during installation, and then the PCB board is fixed to the case or shell. In addition, when PCB boards of multiple functional modules need to be used in combination, they are usually fixed together using mounting screw holes. At this time, the mounting holes will be in direct contact with multiple PCB boards.

[0003] Since the external environment (casing or shell) is very complex, when multiple substrates are used in combination, the mounting holes, as channels that directly connect the PCB board and the external environment (including the casing or shell), can easily become paths for electromagnetic interference propagation. Secondly, because the mounting holes are in direct contact with the PCB board, electromagnetic interference will flow into other PCB boards through the mounting holes. In particular, the casing (shell) will also bring external electromagnetic interference. These adverse factors will enter the PCB board through the mounting holes, which will in turn affect the signal quality of the PCB board, causing electromagnetic interference problems on the entire board, and directly affecting the normal use of the PCB board. Utility Model Content

[0004] In order to overcome the deficiencies of the prior art, the utility model provides a PCB structure capable of shielding external electromagnetic interference, so as to solve the problem that the electromagnetic interference easily flows into the PCB board through the mounting holes.

[0005] The technical solution of the utility model is as follows: A PCB structure capable of shielding external electromagnetic interference comprises a substrate, a jumper resistor and a mounting hole arranged on the substrate, the surface layer of the substrate is provided with a first copper sheet, the bottom layer of the substrate is provided with a second copper sheet, the first copper sheet and the second copper sheet respectively cover the peripheral area of ​​the mounting hole, the substrate is provided with a plurality of via holes arranged around the periphery of the mounting hole, the plurality of via holes are used to connect the first copper sheet and the second copper sheet, one end of the jumper resistor is connected to the first copper sheet, and the other end of the jumper resistor is connected to the GND copper sheet in the substrate.

[0006] Furthermore, the substrate is provided with a plurality of solder resist windows and a plurality of steel mesh areas which are arranged around the periphery of the mounting hole, and the plurality of solder resist windows and the plurality of steel mesh areas are arranged in one-to-one correspondence, and in the orthographic projection direction of the substrate, the solder resist windows and the steel mesh areas overlap.

[0007] Furthermore, the solder resist window and the steel mesh area are arranged between any two adjacent via holes.

[0008] Furthermore, a plurality of GND holes are provided in the substrate, the plurality of GND holes are evenly arranged, and the GND copper sheet covers the peripheral areas of the plurality of GND holes.

[0009] Furthermore, at least six GND holes are provided, and the diameters of the six GND holes are 0.3 mm to 0.5 mm.

[0010] Furthermore, the diameter of the via hole is 0.5 mm.

[0011] Furthermore, the distance between the first copper sheet and the signal line in the substrate is greater than or equal to 1 mm, and the distance between the second copper sheet and the signal line in the substrate is greater than or equal to 1 mm.

[0012] The utility model according to the above scheme has the following beneficial effects: a PCB structure capable of shielding external electromagnetic interference, comprising a substrate, a jumper resistor and a mounting hole arranged on the substrate, the surface layer of the substrate is provided with a first copper sheet, the bottom layer of the substrate is provided with a second copper sheet, the first copper sheet and the second copper sheet respectively cover the peripheral area of ​​the mounting hole, the substrate is provided with a plurality of vias arranged around the periphery of the mounting hole, the plurality of vias are used to connect the first copper sheet and the second copper sheet, one end of the jumper resistor is connected to the first copper sheet, and the other end of the jumper resistor is connected to the GND copper sheet in the substrate. When the external electromagnetic interference signal enters the PCB board through the mounting hole, the jumper resistor will form an impedance, isolating or weakening the electromagnetic interference signal, thereby preventing the electromagnetic interference signal from affecting the circuit in the board. Such a design can not only reduce the external electromagnetic interference signal, but also effectively reduce or isolate the electromagnetic interference signal entering the PCB board through the mounting hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1This is one of the structural schematic diagrams of a PCB structure capable of shielding external electromagnetic interference in an embodiment of the utility model;

[0015] Figure 2 This is a second structural schematic diagram of a PCB structure capable of shielding external electromagnetic interference in an embodiment of the utility model.

[0016] In the figure, 1. substrate; 2. jumper resistor; 3. mounting hole; 4. first copper sheet; 5. second copper sheet; 6. via; 7. GND copper sheet; 8. solder mask window; 9. steel mesh area; 10. GND hole. DETAILED DESCRIPTION

[0017] The following detailed description and drawings of the embodiments of the present invention are used to illustrate the principle of the present invention, but cannot be used to limit the scope of the present invention, that is, the present invention is not limited to the embodiments described.

[0018] In order to better understand the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0019] In the electronics manufacturing industry, printed circuit boards (PCB boards) are the core components of electronic products. They not only carry electronic components, but are also key components for signal transmission and electrical connection. Among them, the mounting holes 3 play an important role in the design and manufacture of PCB boards. The main function of the mounting holes 3 is to provide stable mechanical fixation for the PCB board to ensure that its position in the casing or housing is stable and reliable. Specifically, by inserting screws into the mounting holes 3 and supplemented with gaskets, it can be ensured that the PCB board fits tightly on the casing or housing to prevent loosening or damage caused by vibration or impact. This fixing method is not only simple and effective, but also can provide good mechanical stability. When the PCB boards of multiple functional modules need to be used in combination, by reserving corresponding mounting holes 3 during design and fixing multiple PCB boards together with screws, close connection and collaborative work between modules can be achieved. This combination method not only improves the integration of the device, but also enhances the stability and reliability of the system. Since the mounting hole 3 directly connects the PCB board and the external environment (such as a casing or shell), it can easily become a path for the propagation of electromagnetic interference signals. Especially when multiple substrates 1 are used in combination, the mounting hole 3 may become a channel for the electromagnetic interference signal to propagate from one PCB board to another. The electromagnetic interference signal may flow into the interior of the PCB board through the mounting hole 3, affecting the signal quality of the circuit board and even causing electromagnetic interference problems on the entire board, thereby affecting the normal use of the PCB board.

[0020] Based on this, the embodiment of the present invention provides a PCB structure that can shield external electromagnetic interference, see Figure 1and Figure 2 As shown, a PCB structure capable of shielding external electromagnetic interference includes a substrate 1, a jumper resistor 2, and a mounting hole 3 arranged on the substrate 1. The surface layer of the substrate 1 is provided with a first copper sheet 4, and the bottom layer of the substrate 1 is provided with a second copper sheet 5. The first copper sheet 4 and the second copper sheet 5 respectively cover the peripheral area of ​​the mounting hole 3. The substrate 1 is provided with a plurality of via holes 6 arranged around the periphery of the mounting hole 3. The plurality of via holes 6 are used to connect the first copper sheet 4 and the second copper sheet 5. One end of the jumper resistor 2 is connected to the first copper sheet 4, and the other end of the jumper resistor 2 is connected to the GND copper sheet 7 in the substrate 1. When the external electromagnetic interference signal enters the PCB board through the mounting hole 3, the jumper resistor 2 will form an impedance to isolate or weaken the electromagnetic interference signal, thereby preventing the electromagnetic interference signal from affecting the circuit in the board. Such a design can not only reduce the external electromagnetic interference signal, but also effectively reduce or isolate the electromagnetic interference signal entering the PCB board through the mounting hole 3.

[0021] Specifically, an embodiment of the utility model provides a PCB structure that can shield external electromagnetic interference. A first copper sheet 4 and a second copper sheet 5 are respectively arranged on the surface layer and the bottom layer of the substrate 1, and the first copper sheet 4 and the second copper sheet 5 cover the peripheral area of ​​the mounting hole 3, so as to form an electromagnetic shielding layer. Such a design can significantly reduce the possibility of external electromagnetic interference signals entering the interior of the PCB board through the mounting hole 3. Secondly, a plurality of via holes 6 arranged around the mounting hole 3 are provided on the substrate 1, so as to connect the first copper sheet 4 and the second copper sheet 5 through the via holes 6, so as to form a closed electromagnetic shielding ring. Such a structure can more effectively reduce the probability of external electromagnetic interference signals penetrating into the interior of the PCB board through the mounting hole 3. These via holes 6 not only enhance the electrical connection between the first copper sheet 4 and the second copper sheet 5, but also enhance the continuity and integrity of the shielding layer, thereby further improving the electromagnetic shielding effect.

[0022] In this embodiment, the substrate 1 is provided with a plurality of solder resist windows 8 and a plurality of steel mesh areas 9 arranged around the periphery of the mounting hole 3, and the plurality of solder resist windows 8 and the plurality of steel mesh areas 9 are arranged in one-to-one correspondence, and in the orthographic projection direction of the substrate 1, the solder resist windows 8 and the steel mesh areas 9 overlap. Specifically, the solder resist windows 8 and the steel mesh areas 9 correspond in number to each other, that is, each solder resist window 8 has a corresponding steel mesh area 9, and in the orthographic projection direction of the substrate 1, the solder resist windows 8 and the steel mesh areas 9 overlap each other in position. Specifically, the solder resist windows 8 refer to the size of the exposed copper portion at the position to be welded, that is, the size of the portion not covered with ink. The steel mesh area 9 is a specific area for applying solder paste (Solder Paste) on the substrate 1. In SMT (surface mount technology) and certain through-hole welding processes, solder paste is used as a temporary adhesive and conductive medium during welding. The stencil is usually a thin metal sheet with a plurality of openings, which correspond to the stencil area 9 on the substrate 1 so that the solder paste can be accurately applied to the stencil area 9 during the printing process.

[0023] During the processing, by brushing solder paste on the steel mesh area 9, it can be ensured that the solder paste is accurately coated on the exposed copper area where the solder mask opening 8 is located. Due to the presence of solder paste, when the screw or other fastener is inserted into the mounting hole 3, the friction force can be increased, thereby improving the installation firmness of the screw. In addition, the solder paste will melt during the welding process to form a firm metal connection, further enhancing the connection reliability between the screw and the substrate 1.

[0024] Preferably, a solder resist window 8 and a steel mesh area 9 are provided between any two adjacent via holes 6 .

[0025] In this embodiment, a plurality of GND holes 10 are arranged in the substrate 1, and the plurality of GND holes 10 are evenly arranged, and the GND copper sheet 7 covers the peripheral area of ​​the plurality of GND holes 10, and at least 6 GND holes 10 are provided, and the aperture of the 6 GND holes 10 is 0.3 mm to 0.5 mm. Preferably, the aperture of the via 6 is 0.5 mm.

[0026] Preferably, the distance between the first copper sheet 4 and the signal line in the substrate 1 is greater than or equal to 1 mm, and the distance between the second copper sheet 5 and the signal line in the substrate 1 is greater than or equal to 1 mm. This design can effectively reduce the electromagnetic coupling between the copper sheet and the signal line, thereby reducing signal interference and ensuring the stability and accuracy of signal transmission.

[0027] The indicated orientation or position relationship is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the product of the application is usually placed when used, or the orientation or position relationship commonly understood by technical personnel in this field, or the orientation or position relationship in which the product of the application is usually placed when used. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply 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 on the present application.

[0028] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the claims attached to the utility model.

[0029] The above is an exemplary description of the utility model patent in conjunction with the accompanying drawings. It is obvious that the implementation of the utility model patent is not limited to the above-mentioned method. As long as various improvements are made by adopting the method concept and technical solution of the utility model patent, or the concept and technical solution of the utility model patent are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.

Claims

1. A PCB structure capable of shielding external electromagnetic interference, characterized in that: The invention comprises a substrate (1), a jumper resistor (2) and a mounting hole (3) arranged on the substrate (1); the surface layer of the substrate (1) is provided with a first copper sheet (4); the bottom layer of the substrate (1) is provided with a second copper sheet (5); the first copper sheet (4) and the second copper sheet (5) respectively cover the peripheral area of ​​the mounting hole (3); the substrate (1) is provided with a plurality of via holes (6) arranged around the periphery of the mounting hole (3); the plurality of via holes (6) are used to connect the first copper sheet (4) and the second copper sheet (5); one end of the jumper resistor (2) is connected to the first copper sheet (4); and the other end of the jumper resistor (2) is connected to a GND copper sheet (7) in the substrate (1).

2. A PCB structure capable of shielding external electromagnetic interference as claimed in claim 1, characterized in that: The substrate (1) is provided with a plurality of solder resist windows (8) and a plurality of steel mesh areas (9) which are arranged around the periphery of the mounting hole (3), and the plurality of solder resist windows (8) and the plurality of steel mesh areas (9) are arranged in a one-to-one correspondence, and in the orthographic projection direction of the substrate (1), the solder resist windows (8) and the steel mesh areas (9) overlap.

3. A PCB structure capable of shielding external electromagnetic interference as claimed in claim 2, characterized in that: The solder resist window (8) and the steel mesh area (9) are provided between any two adjacent via holes (6).

4. A PCB structure capable of shielding external electromagnetic interference as claimed in claim 3, characterized in that: A plurality of GND holes (10) are arranged in the substrate (1), the plurality of GND holes (10) are evenly arranged, and the GND copper sheet (7) covers the peripheral areas of the plurality of GND holes (10).

5. A PCB structure capable of shielding external electromagnetic interference as claimed in claim 4, characterized in that: At least six GND holes (10) are provided, and the diameters of the six GND holes (10) are between 0.3 mm and 0.5 mm.

6. A PCB structure capable of shielding external electromagnetic interference as claimed in claim 4, characterized in that: The diameter of the through hole (6) is 0.5 mm.

7. A PCB structure capable of shielding external electromagnetic interference as claimed in claim 1, characterized in that: The distance between the first copper sheet (4) and the signal line in the substrate (1) is greater than or equal to 1 mm, and the distance between the second copper sheet (5) and the signal line in the substrate (1) is greater than or equal to 1 mm.

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