Circuit board component and electronic device

Abstract

Provided in the embodiments of the present application are a circuit board component and an electronic device. The circuit board component comprises a circuit board, at least one strong interference structure, at least one interference receiving source and at least one electromagnetic bandgap structure, wherein the at least one electromagnetic bandgap structure is arranged on the circuit board, each electromagnetic bandgap structure corresponds to one strong interference structure and one interference receiving source, and each electromagnetic bandgap structure is used for improving an isolation degree between the corresponding interference receiving source and the corresponding strong interference structure. The circuit board component and the electronic device provided in the embodiments of the present application can improve an isolation degree between a strong interference structure and an interference receiving source, so as to reduce the interference of the strong interference structure on the interference receiving source.

Description

Circuit board assemblies and electronic devices

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on September 14, 2023, with application number 202311192428.6 and application name “Circuit Board Assembly and Electronic Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The embodiments of the present application relate to the field of electromagnetic interference technology, and in particular to a circuit board assembly and an electronic device. Background Art

[0003] Currently, electronic devices include a circuit board and a radio frequency module mounted on the circuit board's surface. The circuit board includes a processor, surface traces, connectors, and other components exposed on the circuit board's surface. The radio frequency module is used to receive radio frequency signals. However, when transmitting high-frequency clock signals or high-speed digital signals, these components are susceptible to electromagnetic interference (EMI), which can affect RF reception. Therefore, preventing EMI from affecting RF reception has become a pressing issue.

[0004] Summary of the Invention

[0005] Embodiments of the present application provide a circuit board assembly and an electronic device, which can improve the isolation between a strong interfering structure and an interference source, thereby reducing the interference of the strong interfering structure on the interference source.

[0006] In a first aspect, the present application provides a circuit board assembly comprising a circuit board, at least one strong interference structure, at least one interfered source, and at least one electromagnetic bandgap structure. The at least one electromagnetic bandgap structure is disposed on the circuit board, each electromagnetic bandgap structure corresponding to a strong interference structure and an interfered source, and each electromagnetic bandgap structure is configured to improve isolation between a corresponding interfered source and a corresponding strong interference structure.

[0007] The circuit board assembly provided in the embodiments of the present application utilizes at least one electromagnetic bandgap (EBG) structure on the circuit board. Each EBG structure improves the isolation between the corresponding strong interfering structure and the corresponding interference source, thereby reducing or even eliminating the interference posed by the strong interfering structure on the interference source. Furthermore, the EBG structure does not affect the normal operation of the circuit board, ensuring signal integrity.

[0008] In a possible implementation, each electromagnetic bandgap structure is disposed near a corresponding strong interference structure.

[0009] The circuit board assembly provided in the embodiments of the present application, by placing each electromagnetic bandgap structure near a corresponding strong interference structure, can convert the electromagnetic waves emitted by each strong interference structure into decaying waves (evanescent waves), confining the electromagnetic waves emitted by the strong interference structure to a certain range, suppressing the transmission of the electromagnetic waves, thereby reducing the coupling between the interference source and the strong interference structure, and further improving the isolation between the interference source and the strong interference structure. In addition, suppressing interference at the source end can reduce the difficulty of setting up the electromagnetic bandgap structure and also reduce the difficulty of suppressing interference.

[0010] In a possible implementation, along a direction perpendicular to the thickness direction of the circuit board, each electromagnetic bandgap structure is disposed on a side of the corresponding strong interference structure facing the corresponding interference source.

[0011] In the circuit board assembly provided in the embodiment of the present application, each electromagnetic band gap structure is arranged on the side of the corresponding strong interference structure facing the corresponding interference source along the direction perpendicular to the thickness direction of the circuit board, so that each electromagnetic band gap structure is arranged on the transmission path between the corresponding strong interference structure and the interference source, and the electromagnetic waves emitted by the strong interference structure and moving toward the interference source can be converted into falloff waves to reduce interference.

[0012] In a possible implementation, the circuit board assembly includes a plurality of strong interference structures, and each strong interference structure of at least one strong interference structure among the plurality of strong interference structures corresponds to at least one electromagnetic bandgap structure.

[0013] Each of at least one strong interference structure among the multiple strong interference structures in the circuit board assembly provided in the embodiment of the present application corresponds to at least one electromagnetic band gap structure, which can ensure that the electromagnetic interference generated by the strong interference structure that interferes with the interference source can be suppressed by the corresponding electromagnetic band gap structure to ensure the performance of the circuit board assembly.

[0014] In a possible implementation, each strong interference structure is any one of the following structures: a via, a chip, a surface trace, a connector, a cavity structure, or a buckle seat.

[0015] In one possible embodiment, at least one strong interference structure is a surface trace, wherein: when each surface trace corresponds to multiple electromagnetic bandgap structures, the multiple electromagnetic bandgap structures corresponding to each surface trace are arranged on the same side of the surface trace in a direction perpendicular to the direction of the circuit board. Alternatively, when each surface trace corresponds to multiple electromagnetic bandgap structures, the multiple electromagnetic bandgap structures corresponding to each surface trace are arranged on opposite sides of the surface trace in a direction perpendicular to the direction of the circuit board. Such an arrangement can convert the electromagnetic waves emitted by the surface trace into decay waves, thereby suppressing the circuit board propagation generated by the surface trace, and further reducing the interference of the surface trace on the victim. In addition, by improving the isolation between the surface trace and the victim through the electromagnetic bandgap structure, not only can the electromagnetic interference of the surface trace on the victim be reduced, but also the interference cost can be reduced.

[0016] In a possible implementation, at least one strong interference structure is a cavity structure, and the electromagnetic band gap structure corresponding to each cavity structure is arranged at an edge of the cavity structure.

[0017] The electromagnetic band gap structure corresponding to the cavity structure of the circuit board assembly provided in the embodiment of the present application is arranged at the edge of the cavity structure, which can convert the near-field propagation wave in the cavity structure into a falloff wave, suppress the propagation of near-field electromagnetic waves, reduce spatial coupling, and thus improve the isolation between the cavity structure and the interference source.

[0018] In a possible implementation, along a direction perpendicular to the thickness direction of the circuit board, the electromagnetic bandgap structure corresponding to each cavity structure is arranged on a side of the cavity structure facing the interference source corresponding to the electromagnetic bandgap structure.

[0019] The electromagnetic band gap structure corresponding to each cavity structure in the circuit board assembly provided in the embodiment of the present application is arranged on the side of the cavity structure facing the corresponding interference source, which can ensure that the near-field electromagnetic waves leaving the cavity structure and moving toward the interference source can be converted into dropout waves, thereby suppressing the propagation of near-field electromagnetic waves and improving the isolation between the interference source and the cavity structure.

[0020] In a possible embodiment, the circuit board assembly further includes a heat sink. The circuit board and the heat sink are arranged side by side and spaced apart along the thickness direction of the circuit board. The circuit board and the heat sink are electrically connected and form a cavity structure with the heat sink.

[0021] When the heat sink and the circuit board in the circuit board assembly provided in the embodiment of the present application enclose a cavity structure, the near-field propagation wave in the cavity structure can be converted into a falloff wave through the electromagnetic band gap structure, thereby suppressing the propagation of near-field electromagnetic waves and reducing spatial coupling, thereby improving the isolation between the strong interference structure and the interfered source.

[0022] In one possible embodiment, each electromagnetic bandgap structure includes a ground layer, a metal layer, and an electrical connection structure. Along the thickness direction of the circuit board, the ground layer and the metal layer are respectively arranged on opposite sides of the circuit board, and the electrical connection structure electrically connects the ground layer and the metal layer.

[0023] The circuit board assembly provided in the embodiment of the present application electrically connects the electromagnetic bandgap structure of the ground layer and the metal layer through the electrical connection structure, which can improve the isolation between the strong interference structure and the interference source, and can reduce or shield the interference of the strong interference structure on the interference source.

[0024] In one possible embodiment, the metal layer includes multiple sub-metal segments, and the electrical connection structure includes multiple sub-structures. The multiple sub-metal segments are arranged side by side and spaced apart in a direction perpendicular to the thickness of the circuit board. The multiple sub-structures correspond one-to-one to the multiple sub-metal segments, and each sub-structure is electrically connected to the ground layer and the corresponding sub-metal segment.

[0025] The metal layer in the circuit board assembly provided in the embodiment of the present application is composed of multiple sub-metal segments, and each sub-metal segment is electrically connected to the ground layer through a corresponding substructure, so that each electromagnetic band gap structure can be equivalent to a parallel LC resonant circuit with relatively strong local resonance characteristics, so as to increase the resonance performance of the unit. Then, the characteristic of infinite reactance when the unit resonates is utilized to prevent the propagation of electromagnetic waves near the resonant frequency, so as to form a frequency band gap, thereby achieving the purpose of improving the isolation between the strong interference structure and the interference source.

[0026] In one possible embodiment, the circuit board includes at least one insulating layer and at least one conductive layer. When there is only one conductive layer, the insulating layer is one, and the conductive layer and the insulating layer are stacked along the thickness of the circuit board. Alternatively, when there are multiple conductive layers, an insulating layer is provided between two adjacent conductive layers along the thickness of the circuit board.

[0027] The circuit board in the circuit board assembly provided in the embodiment of the present application can be a single-layer board, a double-layer board or a multi-layer board. By setting an electromagnetic bandgap structure on the circuit board, the interference of the strong interference structure on the interference source can be reduced.

[0028] In a possible implementation, the circuit board includes two conductive layers and an insulating layer. Along the thickness direction of the circuit board, the insulating layer is disposed between the two conductive layers.

[0029] When the circuit board assembly provided in the embodiments of the present application is a double-layer board, the exposed surface traces can be suppressed by the electromagnetic bandgap structure, preventing the surface traces from interfering with the source of interference. Furthermore, by using the electromagnetic bandgap structure to address electromagnetic interference caused by surface traces, shielding elements such as shielding covers are no longer necessary, thus reducing costs.

[0030] In a possible implementation, each interfered source is any one of the following modules: a liquid crystal display module, a camera module, or a radio frequency module.

[0031] The circuit board assembly provided in the embodiment of the present application can avoid affecting the structure of the radio frequency module, or avoid screen distortion of the liquid crystal display module, or avoid camera freeze by setting an electromagnetic band gap structure on the circuit board to improve the isolation between the interference source and the strong interference structure.

[0032] A second aspect of the present application provides an electronic device, comprising a circuit board assembly as described in any one of the first aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG1 is a schematic diagram of a first structure for reducing interference in the related art;

[0034] FIG2 is a schematic diagram of a second structure for reducing interference in the related art;

[0035] Figure 3 shows the change in isolation before and after the use of common-mode inductors;

[0036] FIG4 is a schematic structural diagram of a first circuit board assembly provided in an embodiment of the present application;

[0037] FIG5 is a schematic structural diagram of a second circuit board assembly provided in an embodiment of the present application;

[0038] FIG6 is a schematic structural diagram of a third circuit board assembly provided in an embodiment of the present application;

[0039] FIG7 is a schematic structural diagram of a first electromagnetic bandgap structure provided in an embodiment of the present application;

[0040] FIG8 is a schematic structural diagram of a second electromagnetic bandgap structure provided in an embodiment of the present application;

[0041] FIG9 is a simulation diagram of the electromagnetic bandgap structure shown in FIG7 ;

[0042] FIG10 is an equivalent circuit diagram of the electromagnetic bandgap structure shown in FIG7 ;

[0043] FIG11 is a diagram showing the resonance characteristics of the electromagnetic bandgap structure shown in FIG7 ;

[0044] FIG12 is a frequency diagram of the electromagnetic bandgap structure in FIG7;

[0045] FIG13 is a diagram showing the isolation effect before and after the electromagnetic bandgap structure shown in FIG7 is used;

[0046] FIG14 is a schematic structural diagram of the circuit board in FIG6 .

[0047] Description of reference numerals:

[0048] 100. Circuit board assembly;

[0049] 10. Circuit board; 11. Insulation layer; 12. Conductive layer;

[0050] 20. Electromagnetic band gap structure; 21. Ground layer; 22. Metal layer; 221. Sub-metal segment; 23. Electrical connection structure; 231. Sub-structure;

[0051] 30. Disturbance source;

[0052] 40. Strong interference structure; 41. Surface routing; 42. Cavity structure;

[0053] 50. Radiator. DETAILED DESCRIPTION

[0054] Currently, the clock frequencies of terminal products, such as routers, have reached microwave frequencies. Short traces on chips, modules, and printed circuit boards (PCBs) can easily act as antennas, radiating noise into space and causing interference to RF communications. Furthermore, the use cases involve a large amount of digital signal interaction, transmission, and processing within the system. The transmission of data signals can also interfere with RF reception, thus affecting the normal communication experience. Therefore, in scenarios with high-frequency clocks and / or high-speed data transmission, terminal products need to consider interference issues.

[0055] FIG1 is a schematic diagram of the first structure for reducing interference in the related art. Referring to FIG1 , when the processor 110 and the WIFI module 120 are performing data exchange, a common-mode inductor 130 is installed on the differential line pair of the signal output to filter out the common-mode noise that interferes with the radio frequency communication, thereby achieving compatibility between digital and radio frequency. FIG2 is a schematic diagram of the second structure for reducing interference in the related art. Referring to FIG2 , the lines for transmitting high-frequency clock signals and high-speed signals (as shown in FIG2 140 ) are routed on the inner layer as much as possible, and are grounded on the top, bottom, left, and right sides (as shown in FIG2 ). The surface lines that cannot be routed on the inner layer are also shielded so that they cannot be received by the radio frequency module through spatial radiation. However, these methods all have the problem of increased costs. In addition, interference processing through common-mode inductors 130 only slightly improves the isolation of radio frequency interference propagation in space. As shown in Figure 3, the actual benefit of using common-mode inductors 130 to improve the isolation of radio frequency interference propagation in space is only 2dB. Figure 3 shows the isolation change before and after the use of common-mode inductors. In Figure 3, A represents the isolation change curve without the use of common-mode inductors 130, and B represents the isolation change curve with the use of common-mode inductors 130. In addition, due to the frequency characteristics of filtering, it can often only be optimized for interference within a certain frequency range. Interference at multiple frequencies requires further increasing the number of common-mode inductors 130, resulting in further cost increases. Therefore, how to solve electromagnetic interference while avoiding the creation of new problems has become an urgent problem to be solved.

[0056] In view of this, embodiments of the present application provide a circuit board assembly 100 and an electronic device that can improve the isolation between a strong interfering structure 40 and a victim 30, thereby reducing the interference of the strong interfering structure 40 on the victim 30. For example, when the strong interfering structure 40 is a surface trace 41, in scenarios with high-frequency clocks and / or high-speed data transmission, the interference of the surface trace 41 on the victim 30 is reduced.

[0057] An electronic device provided in an embodiment of the present application includes a housing and a circuit board assembly 100. At least a portion of the circuit board assembly 100 is disposed inside the housing.

[0058] Among them, the electronic devices provided in the embodiments of the present application may include but are not limited to routers, televisions, mobile phones, tablet computers, laptop computers, desktop computers, communication devices, etc. In the embodiments of the present application, a router is used as an example for explanation.

[0059] The circuit board assembly 100 provided in the embodiment of the present application is described in detail below with reference to the accompanying drawings.

[0060] FIG4 is a schematic diagram of the structure of the first circuit board assembly provided in an embodiment of the present application. Referring to FIG4 , the circuit board assembly 100 provided in an embodiment of the present application includes a circuit board 10, at least one strong interference structure 40, at least one interfered source 30, and at least one electromagnetic bandgap structure 20. The at least one electromagnetic bandgap structure 20 is disposed on the circuit board 10, and each electromagnetic bandgap structure 20 corresponds to a strong interference structure 40 and an interfered source 30. Each electromagnetic bandgap structure 20 is used to improve the isolation between the corresponding interfered source 30 and the corresponding strong interference structure 40.

[0061] Strong interference structure 40 refers to a structure that emits electromagnetic waves to interfere with victim 30, and may include, but is not limited to, vias, chips, surface traces 41, connectors, cavity structures 42, or buckle sockets. For example, as shown in FIG4 , strong interference structure 40 is surface traces 41.

[0062] There is no limitation on the specific number of the strong interference structures 40 . For example, as shown in FIG. 4 , the number of the strong interference structure 40 is one. Of course, the number of the strong interference structure 40 is not limited to one.

[0063] There is no limitation on the specific number of victim sources 30. For example, as shown in FIG4 , there is one victim source 30. Of course, in some embodiments, there may be multiple victim sources 30. When there are multiple victim sources 30, the number of electromagnetic bandgap structures 20 corresponding to each victim source 30 may be the same or different.

[0064] The disturbed source 30 refers to a device that is easily disturbed by electromagnetic interference, for example, it may include but is not limited to a radio frequency module, a camera module or a liquid crystal display module. In the embodiment of the present application, the radio frequency module is taken as an example to illustrate the above-mentioned disturbed source 30. The electromagnetic band gap structure 20 can improve the isolation between the radio frequency module and the strong interference structure 40, reduce the interference of the strong interference structure 40 on the radio frequency module, and ensure the reception of radio frequency communication. In addition, in some embodiments, when the disturbed source 30 is a camera module, the electromagnetic band gap structure 20 can improve the isolation between the camera module and the strong interference structure 40, reduce the interference of the strong interference structure 40 on the camera module, and avoid the camera module from freezing. In addition, when the disturbed source 30 is a liquid crystal display module, the electromagnetic band gap structure 20 can improve the isolation between the liquid crystal display module and the strong interference structure 40, reduce the interference of the strong interference structure 40 on the liquid crystal display, and avoid the problem of screen distortion in the liquid crystal display module.

[0065] There is no limitation on the specific number of the electromagnetic bandgap structures 20 , and the number may include but is not limited to one, two, three, four, five, etc. For example, as shown in FIG4 , the number of the electromagnetic bandgap structures 20 is four.

[0066] In the embodiment of the present application, by providing at least one electromagnetic bandgap structure 20 on the circuit board 10, each electromagnetic bandgap structure 20 corresponds to a strong interference structure 40 and a victim 30, and each electromagnetic bandgap structure 20 can improve the isolation between the corresponding strong interference structure 40 and the corresponding victim 30, thereby reducing the interference of the strong interference structure 40 on the victim 30. In addition, reducing the interference of the strong interference structure 40 on the victim 30 by the electromagnetic bandgap structure 20 does not increase the cost of the circuit board assembly 100, and can effectively balance interference and cost. In addition, providing the electromagnetic bandgap structure 20 on the circuit board 10 does not affect the performance of the circuit board 10, can ensure signal integrity, and meet usage requirements.

[0067] In the embodiment of the present application, the electromagnetic bandgap structure 20 (EBG) can form a high-impedance surface, converting the electromagnetic waves that interfere with the victim 30 into decaying waves (evanescent waves), so that the victim 30 is not affected by electromagnetic interference, thereby improving the isolation between the victim 30 and the strong interfering structure 40.

[0068] Continuing to refer to FIG. 4 , each EBG structure 20 is disposed near a corresponding strong interference structure 40 .

[0069] Of course, in some possible implementations, each electromagnetic bandgap structure 20 may also be disposed near the corresponding victim 30 (not shown in the figure). Alternatively, in some possible implementations, each electromagnetic bandgap structure 20 may also be disposed between the corresponding victim 30 and the corresponding strong interference structure 40 in a direction perpendicular to the thickness direction of the circuit board 10 (not shown in the figure).

[0070] Accordingly, each electromagnetic band gap structure 20 is disposed near a corresponding strong interference structure 40, near a corresponding interfered source 30, or between a corresponding strong interference structure 40 and the interfered source 30, thereby improving the isolation between the interfered source 30 and the strong interference structure 40. However, disposing each electromagnetic band gap structure 20 near a corresponding strong interference structure 40 can suppress interference at the source end, thereby reducing the difficulty of disposing the electromagnetic band gap structure 20 and also reducing the difficulty of suppressing interference.

[0071] Continuing to refer to Figure 4, each electromagnetic band gap structure 20 is set near the corresponding strong interference structure 40, and the electromagnetic waves emitted by each strong interference structure 40 can be converted into decay waves (evanescent waves) at the source end, and the electromagnetic waves emitted by the strong interference structure 40 can be limited to a certain range, thereby suppressing the transmission of electromagnetic waves, thereby reducing the coupling degree between the disturbed source 30 and the strong interference structure 40, and then improving the isolation between the disturbed source 30 and the strong interference structure 40.

[0072] Each electromagnetic band gap structure 20 is arranged near the corresponding strong interference structure 40 or the corresponding interference source 30. The "near" can be understood as follows: along the direction perpendicular to the thickness direction of the circuit board 10, each electromagnetic band gap structure 20 can be arranged side by side and spaced apart from the corresponding strong interference structure 40 or the corresponding interference source 30 (as shown in FIG4 ), or each electromagnetic band gap structure 20 can be arranged side by side and in contact with the corresponding strong interference structure 40 or the corresponding interference source 30, or along the thickness direction of the circuit board 10, the projection of each electromagnetic band gap structure 20 partially overlaps with the projection of the corresponding strong interference structure 40 or the projection of the corresponding interference source 30. In other words, along the direction perpendicular to the thickness direction of the circuit board 10, the "near" can mean that the spacing between each electromagnetic band gap structure 20 and one of the corresponding interference source 30 and the corresponding strong interference structure 40 is smaller than the spacing between the other. For example, as shown in FIG4 , each electromagnetic band gap structure 20 is arranged near the corresponding strong interference structure 40, and the spacing between the strong interference structure 40 and the electromagnetic band gap structure 20 is smaller than the spacing between the interference source 30 and the electromagnetic band gap structure 20.

[0073] In some possible implementations, referring to FIG4 , each electromagnetic band gap structure 20 can be disposed on a side of the corresponding strong interfering structure 40 that faces the corresponding interference source 30, along a direction perpendicular to the thickness direction of the circuit board 10. Accordingly, each electromagnetic band gap structure 20 is disposed on the transmission path between the corresponding strong interfering structure 40 and the interference source 30, and the electromagnetic waves emitted by the strong interfering structure 40 and moving toward the interference source 30 can be converted into decay waves to reduce interference.

[0074] When each strong interference structure 40 corresponds to one or more EBG structures 20 , all EBG structures 20 corresponding to each strong interference structure 40 are arranged on the side of the strong interference structure 40 facing the interference source 30 along a direction perpendicular to the thickness direction of the circuit board 10 .

[0075] Of course, when each strong interference structure 40 corresponds to multiple electromagnetic band gap structures 20, a part of the multiple electromagnetic band gap structures 20 corresponding to each strong interference structure 40 can be set on the side of the strong interference structure 40 facing the interference source 30, and the other part can also be set on the other side of the strong interference structure 40.

[0076] FIG5 is a schematic diagram of the structure of a second circuit board assembly provided in an embodiment of the present application. In one possible implementation, the circuit board assembly 100 may include multiple strong interference structures 40. For example, as shown in FIG5 , the circuit board assembly 100 includes two strong interference structures 40. Of course, the specific number of strong interference structures 40 is not limited to two. Each strong interference structure 40 of at least one of the multiple strong interference structures 40 corresponds to at least one electromagnetic band gap structure 20. In some embodiments, a portion of the multiple strong interference structures 40 of the circuit board assembly 100 may correspond to an electromagnetic band gap structure 20, while another portion may not correspond to an electromagnetic band gap structure 20. For example, as shown in FIG5 , one strong interference structure 40 corresponds to four electromagnetic band gap structures 20, while another strong interference structure 40 does not correspond to an electromagnetic band gap structure 20. Alternatively, in some embodiments, each of the multiple strong interference structures 40 corresponds to an electromagnetic band gap structure 20. Accordingly, when the circuit board assembly 100 includes multiple strong interference structures 40, the electromagnetic band gap structure 20 improves the isolation between the strong interference structure 40 that interferes with the interfered source 30 and the interfered source 30, thereby reducing the interference on the interfered element 30.

[0077] When there are multiple strong interference structures 40 that interfere with the interfered source 30 , the number of electromagnetic bandgap structures 20 corresponding to each strong interference structure 40 may be the same or different, and there is no limitation here.

[0078] In some embodiments, when there are multiple strong interference structures 40 that interfere with the same interfered source 30, at least two strong interference structures 40 may also share at least one electromagnetic band gap structure 20 (not shown in the figure). For example, two strong interference structures 40 share one electromagnetic band gap structure 20 to improve the isolation between the two strong interference structures 40 and the same interfered source 30.

[0079] In the embodiment of the present application, since each strong interference structure 40 may include, but is not limited to, a via, a surface trace 41, a cavity structure 42, a connector, or a chip, when the circuit board assembly 100 includes multiple strong interference structures 40, the specific type of the multiple strong interference structures 40 of the circuit board assembly 100 is at least one. In one embodiment, the multiple strong interference structures 40 are all surface traces 41. Alternatively, in one embodiment, the multiple strong interference structures 40 include surface traces 41 and cavity structures 42. Alternatively, in one embodiment, the multiple strong interference structures 40 include surface traces 41, cavity structures 42, and vias.

[0080] In some possible implementations, at least one of the multiple strong interference structures 40 of the circuit board assembly 100 is a surface trace 41. For example, the circuit board assembly 100 includes three strong interference structures 40, one of which is a surface trace 41, or all three strong interference structures 40 may be surface traces 41. When each surface trace 41 corresponds to multiple electromagnetic band gap structures 20, the multiple electromagnetic band gap structures 20 corresponding to each surface trace 41 are arranged on the same side of the surface trace 41 along a direction perpendicular to the direction of the circuit board 10, as shown in FIG.

[0081] Alternatively, in some possible implementations, at least one of the multiple strong interference structures 40 of the circuit board assembly 100 is a surface trace 41. When each surface trace 41 corresponds to multiple electromagnetic band gap structures 20, the multiple electromagnetic band gap structures 20 corresponding to each surface trace 41 are disposed on opposite sides of the surface trace 41 (not shown in the figure) along a direction perpendicular to the direction of the circuit board 10.

[0082] In summary, the multiple electromagnetic bandgap structures 20 corresponding to each surface trace 41, disposed on the same side or opposite sides of the surface trace 41, can convert the electromagnetic waves emitted by the surface trace 41 into fading waves, thereby suppressing the propagation of the surface trace 41 on the circuit board 10, and further reducing the interference of the surface trace 41 on the victim 30. In addition, the electromagnetic bandgap structure 20 improves the isolation between the surface trace 41 and the victim 30, which not only reduces the electromagnetic interference of the surface trace 41 on the victim 30, but also reduces the interference cost.

[0083] FIG6 is a schematic diagram of the structure of a third circuit board assembly provided in an embodiment of the present application. In some possible implementations, at least one of the multiple strong interference structures 40 of the circuit board assembly 100 is a cavity structure 42. For example, as shown in FIG6 , the circuit board assembly 100 includes three strong interference structures 40, one of which is a cavity structure 42. Of course, the number of cavity structures 42 may also be two or three. The electromagnetic bandgap structure 20 corresponding to each cavity structure 42 is disposed at the edge of the cavity structure 42.

[0084] Correspondingly, the electromagnetic band gap structure 20 corresponding to each cavity structure 42 is arranged at the edge of the corresponding cavity structure 42, which can convert the near-field propagation wave in the cavity structure 42 into a decay wave, thereby suppressing the propagation of near-field electromagnetic waves and reducing spatial coupling, thereby improving the isolation between the cavity structure 42 and the disturbed source 30.

[0085] The edge of the cavity structure 42 can be understood as the boundary of the projection of the cavity structure 42 along the thickness direction of the circuit board 10 .

[0086] The principle by which the cavity structure 42 interferes with the victim 30 can be understood as follows: the electromagnetic wave leaving the cavity structure 42 will not become a falloff wave. In other words, even if the electromagnetic wave about to leave the cavity structure 42 has already become a falloff wave, the amplitude of the electromagnetic wave will not attenuate after leaving the cavity structure 42, causing the victim 30 to be disturbed. Therefore, by providing the electromagnetic bandgap structure 20 at the edge of the cavity structure 42, it can be ensured that the near-field propagation wave leaving the cavity structure 42 is converted into a falloff wave, thereby suppressing the propagation of the near-field electromagnetic wave.

[0087] When at least one of the multiple strong interference structures 40 of the circuit board assembly 100 is a cavity structure 42 and the remaining strong interference structures 40 are non-cavity structures 42, at least one of the remaining strong interference structures 40 can be set inside the cavity structure 42, or the cavity structure 42 can also be set between the interference source 30 and at least one of the remaining strong interference structures 40.

[0088] In some embodiments, as shown in FIG6 , at least a portion of each of the at least one EBG structures 20 corresponding to each cavity structure 42 may be disposed within the cavity defined by the cavity structure 42. In other words, along the thickness direction of the circuit board 10, the projection of the EBG structure 20 corresponding to each cavity structure 42 at least partially overlaps with the projection of the cavity structure 42.

[0089] Alternatively, in some embodiments, each of the at least one EBG structures 20 corresponding to each cavity structure 42 may also be disposed outside the cavity defined by the cavity structure 42 (not shown). In other words, along the thickness direction of the circuit board 10, the projection of the EBG structure 20 corresponding to each cavity structure 42 does not overlap with the projection of the cavity structure 42.

[0090] Continuing with FIG6 , along a direction perpendicular to the thickness direction of the circuit board 10, the electromagnetic band gap structure 20 corresponding to each cavity structure 42 is disposed on the side of the cavity structure 42 facing the victim 30 corresponding to the electromagnetic band gap structure 20. This arrangement ensures that near-field electromagnetic waves leaving the cavity structure 42 and heading toward the victim 30 can be converted into dropout waves, thereby suppressing the propagation of near-field electromagnetic waves and improving the isolation between the cavity structure 42 and the victim 30.

[0091] Of course, when the number of electromagnetic band gap structures 20 corresponding to each cavity structure 42 is multiple, a part of the multiple electromagnetic band gap structures 20 corresponding to each cavity structure 42 can be arranged on one side of the cavity structure 42 facing the interference source 30 corresponding to the electromagnetic band gap structure 20 in a direction perpendicular to the thickness direction of the circuit board 10, and the other part can be arranged on the other side of the cavity structure 42.

[0092] In the embodiment of the present application, the specific structure of the cavity structure 42 is not limited here. The following describes how to define the cavity structure 42.

[0093] In some embodiments, as shown in FIG6 , the circuit board assembly 100 may further include a heat sink 50. The circuit board 10 and the heat sink 50 are arranged side by side and spaced apart along the thickness direction of the circuit board 10. The circuit board 10 is electrically connected to the heat sink 50 and forms a cavity structure 42 with the heat sink 50. Accordingly, when the heat sink 50 and the circuit board 10 form a cavity structure 42, the electromagnetic bandgap structure 20 provided at the edge of the cavity structure 42 can convert the near-field propagation wave in the cavity structure 42 into a decay wave, thereby suppressing the propagation of the near-field electromagnetic wave and reducing spatial coupling, thereby improving the isolation between the strong interference structure 40 and the interfered source 30.

[0094] In which, along the thickness direction of the circuit board 10, the projection of the heat sink 50 can cover the projection of the corresponding electromagnetic band gap structure 20, or the projection of the heat sink 50 partially overlaps with the projection of the corresponding electromagnetic band gap structure 20, or the projection of the heat sink 50 does not overlap with the projection of the corresponding electromagnetic band gap structure 20.

[0095] The heat sink 50 is used to increase the heat exchange area between the heating device disposed on the circuit board 10 and the air, so as to keep the operating temperature of the heating device within a reasonable range. The heating device may include but is not limited to a chip, a memory, etc.

[0096] The specific structure of the heat sink 50 is not limited herein. For example, the heat sink 50 includes a main body and a plurality of plate-like portions, wherein the plurality of plate-like portions are disposed on a first side of the main body, and a second side of the main body is configured to face the heat generating device. The first side and the second side are disposed opposite each other along the thickness direction of the circuit board 10.

[0097] In some embodiments, the circuit board assembly 100 may further include a metal sheet (not shown). The circuit board 10 and the metal sheet are arranged side by side and spaced apart along the thickness direction of the circuit board 10. The circuit board 10 is electrically connected to the metal sheet and forms a cavity structure 42 with the metal sheet. Accordingly, when the metal sheet and the circuit board 10 form the cavity structure 42, the electromagnetic bandgap structure 20 provided at the edge of the cavity structure 42 can convert the near-field propagation waves in the cavity structure 42 into decay waves, thereby suppressing the propagation of near-field electromagnetic waves and reducing spatial coupling, thereby improving the isolation between the strong interfering structure 40 and the interfered source 30.

[0098] In which, along the thickness direction of the circuit board 10, the projection of the metal sheet may cover the projection of the corresponding electromagnetic band gap structure 20, or the projection of the metal sheet partially overlaps with the projection of the corresponding electromagnetic band gap structure 20, or the projection of the metal sheet does not overlap with the projection of the corresponding electromagnetic band gap structure 20.

[0099] It should be noted that the metal sheet and the heat sink 50 may exist at the same time, or the metal sheet and the heat sink 50 may not exist at the same time. In other words, the metal sheet or the heat sink 50 may exist alone.

[0100] FIG7 is a schematic diagram of the structure of the first electromagnetic bandgap structure provided in an embodiment of the present application. In some possible implementations, in combination with FIG6 above and referring to FIG7 , each electromagnetic bandgap structure 20 includes a ground layer 21, a metal layer 22, and an electrical connection structure 23. In particular, along the thickness direction of the circuit board 10, the ground layer 21 and the metal layer 22 are respectively arranged on opposite sides of the circuit board 10, and the electrical connection structure 23 electrically connects the ground layer 21 and the metal layer 22. Accordingly, by adopting such a structure of the electromagnetic bandgap structure 20, the isolation between the strong interference structure 40 and the interfered source 30 can be improved, and the interference of the strong interference structure 40 on the interfered source 30 can be reduced or shielded.

[0101] The metal layer 22 and the interference source 30 can be disposed on the same side or opposite sides of the circuit board 10 along the thickness direction of the circuit board 10. In addition, the metal layer 22 and the strong interference structure 40 can be disposed on the same side or opposite sides of the circuit board 10.

[0102] As shown in FIG7 , the metal layer 22 may include multiple sub-metal segments 221, and the electrical connection structure 23 may include multiple sub-structures 231. The sub-metal segments 221 are arranged side by side and spaced apart in a direction perpendicular to the thickness of the circuit board 10. The sub-structures 231 correspond one-to-one with the sub-metal segments 221, and each sub-structure 231 electrically connects the ground layer 21 to the corresponding sub-metal segment 221.

[0103] Of course, in some embodiments, the metal layer 22 may also be an integral structure. In other words, the metal layer 22 includes a sub-metal segment 221, so that the longitudinal cross-section of each electromagnetic band gap structure 20 is in the shape of an "I", as shown in Figure 8, which is a structural schematic diagram of the second electromagnetic band gap structure provided in an embodiment of the present application.

[0104] In summary, the metal layer 22 in the electromagnetic bandgap structure 20 is composed of one or more sub-metal segments 221, which can improve the isolation between the strong interference structure 40 and the interference source 30, thereby reducing interference. However, if the metal layer 22 is composed of multiple sub-metal segments 221, the interference reduction effect can be further improved.

[0105] Figure 9 is a simulation diagram of the EBG structure shown in Figure 7 , Figure 10 is an equivalent circuit diagram of the EBG structure shown in Figure 7 , Figure 11 is a resonance characteristic diagram of the EBG structure shown in Figure 7 , and Figure 12 is a frequency diagram of the EBG structure shown in Figure 7 . In conjunction with Figure 7 and referring to Figure 9 , the EBG structure 20 can be equivalent to a parallel LC resonant circuit with relatively strong local resonance characteristics (as shown in Figure 10 ), thereby enhancing the resonant performance of the EBG structure 20 . The infinite reactance characteristic of the EBG structure 20 during resonance (as shown in Figure 11 ) is then utilized to prevent electromagnetic waves from propagating near the resonant frequency (as shown in Figure 11 , the resonant frequency is 5.28 GHz), thereby forming a frequency bandgap (as shown in Figure 12 ).

[0106] Furthermore, the electromagnetic bandgap structure 20 is a periodic structure with band-stop characteristics, providing a low-impedance path for high-frequency current (or noise) between the two planes. The AC short circuit between the two reference planes allows noise generated by the interference source plane to quickly form a loop through the local low-impedance path, preventing it from propagating outward, thereby achieving a noise suppression effect.

[0107] Furthermore, noise suppression also reduces electromagnetic radiation. The electromagnetic bandgap structure 20, designed to specifically block high-frequency currents or noise between two planes, can suppress electromagnetic waves of specific frequencies generated by the high-speed circuit board 10. When the high-speed circuit board 10 is operating, electromagnetic waves generated by intermittent or continuous voltage and current variations pass through the electromagnetic bandgap structure 20, designed to a specific frequency. This creates a resonant circuit that suppresses the propagation of electromagnetic waves at the resonant frequency, thereby reducing interference.

[0108] Figure 13 shows the isolation effect before and after the implementation of the electromagnetic bandgap structure shown in Figure 7. C shows the isolation curve using the electromagnetic bandgap structure shown in Figure 7, and D shows the isolation curve without the electromagnetic bandgap structure shown in Figure 7. As shown in Figure 13, by providing the electromagnetic bandgap structure 20 on the circuit board 10, the isolation between the strong interfering structure 40 and the interference source 30 can be improved.

[0109] Figure 14 is a schematic diagram of the structure of the circuit board in Figure 6. As shown in Figure 14 , circuit board 10 includes at least one insulating layer 11 and at least one conductive layer 12. Insulating layer 11 and conductive layer 12 are stacked along the thickness direction of circuit board 10 (e.g., the X direction in Figure 14 ).

[0110] There is no limitation on the specific number of conductive layers 12 and the specific number of insulating layers 11. In one embodiment, when there is one conductive layer 12, the number of insulating layers 11 is one, and the conductive layer 12 and the insulating layer 11 are stacked along the thickness direction of the circuit board 10. In this case, the circuit board 10 is a single-layer board. In one embodiment, when there are multiple conductive layers 12, an insulating layer 11 is provided between two adjacent conductive layers 12 along the thickness direction of the circuit board 10. In this case, the circuit board 10 can be a double-layer board or a multi-layer board. Therefore, when the circuit board 10 is a single-layer board, a double-layer board or a multi-layer board, by providing an electromagnetic bandgap structure 20 on the circuit board 10, the interference of the strong interference structure 40 on the interfered source 30 can be reduced.

[0111] Among them, in the embodiment of the present application, a two-layer board is taken as the above-mentioned circuit board 10 as an example for explanation. As shown in Figure 14, the two-layer board includes two conductive layers 12 and an insulating layer 11. Along the thickness direction of the circuit board 10, an insulating layer 11 is arranged between the two conductive layers 12.

[0112] Since the circuit board 10 is a two-layer board, the wiring of the circuit board 10 is exposed (as shown in FIG6 ), that is, at least one of the two conductive layers 12 includes a surface wiring 41 and is located on the surface of the insulating layer 11. When the surface wiring 41 transmits a high-frequency clock signal or a high-speed digital signal, the surface wiring 41 will generate electromagnetic waves that interfere with the source 30. If a shielding cover or other structure is used to reduce the interference of the surface wiring 41 on the source 30, the shielding cost increased by the shielding cover is much greater than the cost benefit of using a single-layer board or a two-layer board, making the overall benefit negative. However, in the application embodiment, by providing an electromagnetic bandgap structure 20 on the circuit board 10, not only can the isolation between the surface wiring 41 and the source 30 be improved, but the shielding cost is much less than the cost benefit of using a single-layer board or a double-layer board, making the overall benefit positive. Therefore, when the circuit board 10 is a two-layer board or a single-layer board, the isolation between the strong interference structure 40 and the interfered source 30 is improved by the electromagnetic band gap structure 20, which not only reduces the interference of the strong interference structure 40 on the interfered source 30, but also reduces the cost without adding an electromagnetic interference shielding cover.

[0113] Continuing with FIG6 , since the circuit board 10 is a two-layer board, the metal layer 22 and ground layer 21 of each EBG structure 20 can be disposed on opposite sides of the insulating layer 11. The ground layer 21 can be located on the same side of the insulating layer 11 as one of the two conductive layers 12 of the circuit board 10 and arranged side by side along the thickness direction of the circuit board 10. Alternatively, in some embodiments, the ground layer 21 can be integrally formed with one of the two conductive layers 12 of the circuit board 10, as shown in FIG6 . In other words, the ground layer 21 of each EBG structure 20 is part of one of the conductive layers 12 of the circuit board 10.

[0114] It should be noted that, in addition to improving the isolation between the strong interfering structure 40 and the interfered source 30, the electromagnetic bandgap structure 20 can also be used as an isolation structure to improve the isolation between antennas, and the resonant frequency can be designed as required. Furthermore, the electromagnetic bandgap structure 20 can also be used to reduce the impact of electromagnetic emissions such as radio, millimeter waves, and infrared on digital signals.

[0115] In the description of the embodiments of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to a fixed connection, an indirect connection via an intermediate medium, internal communication between two components, or an interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of this application based on specific circumstances.

[0116] In the embodiments of the present application, any device or element referred to or implied must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present application. In the description of the embodiments of the present application, the meaning of "plurality" is two or more, unless otherwise specifically specified.

[0117] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the embodiments of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0118] The term "plurality" in this document refers to two or more. The term "and / or" in this document simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. Furthermore, the character " / " in this document generally indicates an "or" relationship between the related objects; in a formula, the character " / " indicates a "division" relationship between the related objects.

[0119] It will be understood that the various numerical numbers involved in the embodiments of the present application are merely distinctions for the convenience of description and are not intended to limit the scope of the embodiments of the present application.

[0120] It can be understood that in the embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

Claims

1. A circuit board assembly, characterized in that: It includes a circuit board, at least one strong interference structure, at least one interference source and at least one electromagnetic bandgap structure; The at least one electromagnetic bandgap structure is arranged on the circuit board, each of the electromagnetic bandgap structures corresponds to one of the strong interference structures and one of the interfered sources, and each of the electromagnetic bandgap structures is used to improve the isolation between the corresponding interfered source and the corresponding strong interference structure.

2. The circuit board assembly according to claim 1, characterized in that: Each of the electromagnetic band gap structures is arranged near the corresponding strong interference structure.

3. The circuit board assembly according to claim 1 or 2, characterized in that: Along a direction perpendicular to the thickness direction of the circuit board, each of the electromagnetic band gap structures is arranged on a side of the corresponding strong interference structure facing the corresponding interference source.

4. The circuit board assembly according to any one of claims 1 to 3, characterized in that: The circuit board assembly includes a plurality of the strong interference structures, and each of at least one of the plurality of the strong interference structures corresponds to at least one electromagnetic band gap structure.

5. The circuit board assembly according to any one of claims 1 to 4, characterized in that: Each of the strong interference structures is any one of the following structures: a via, a chip, a surface wiring, a connector, a cavity structure or a buckle seat.

6. The circuit board assembly according to claim 5, characterized in that: At least one of the strong interference structures is the surface wiring, wherein: When each of the surface routing lines corresponds to a plurality of the electromagnetic bandgap structures, along a direction perpendicular to the direction of the circuit board, the plurality of the electromagnetic bandgap structures corresponding to each of the surface routing lines are arranged on the same side of the surface routing line; or, When each of the surface routing lines corresponds to a plurality of the electromagnetic bandgap structures, along a direction perpendicular to the direction of the circuit board, the plurality of the electromagnetic bandgap structures corresponding to each of the surface routing lines are arranged on opposite sides of the surface routing line.

7. The circuit board assembly according to claim 5 or 6, characterized in that: At least one of the strong interference structures is the cavity structure, and the electromagnetic band gap structure corresponding to each of the cavity structures is arranged at the edge of the cavity structure.

8. The circuit board assembly according to claim 7, characterized in that: Along a direction perpendicular to the thickness direction of the circuit board, the electromagnetic band gap structure corresponding to each of the cavity structures is arranged on a side of the cavity structure facing the disturbance source corresponding to the electromagnetic band gap structure.

9. The circuit board assembly according to claim 7 or 8, characterized in that: The circuit board assembly also includes a heat sink. Along the thickness direction of the circuit board, the circuit board and the heat sink are arranged side by side and at an interval. The circuit board is electrically connected to the heat sink and forms the cavity structure with the heat sink.

10. The circuit board assembly according to any one of claims 1 to 9, characterized in that: Each of the electromagnetic bandgap structures includes a ground layer, a metal layer and an electrical connection structure. Along the thickness direction of the circuit board, the ground layer and the metal layer are respectively arranged on opposite sides of the circuit board, and the electrical connection structure electrically connects the ground layer and the metal layer.

11. The circuit board assembly according to claim 10, characterized in that: The metal layer includes a plurality of sub-metal segments, and the electrical connection structure includes a plurality of sub-structures; Along a direction perpendicular to the thickness direction of the circuit board, the plurality of sub-metal segments are arranged side by side and at intervals; The plurality of substructures correspond to the plurality of submetal segments one by one, and each of the substructures is electrically connected to the ground layer and the corresponding submetal segment.

12. The circuit board assembly according to any one of claims 1 to 11, characterized in that: The circuit board comprises at least one insulating layer and at least one conductive layer, wherein: When there is one conductive layer, there is one insulating layer, and along the thickness direction of the circuit board, the conductive layer and the insulating layer are stacked; or, When there are multiple conductive layers, one insulating layer is disposed between two adjacent conductive layers along the thickness direction of the circuit board.

13. The circuit board assembly according to claim 12, characterized in that: The circuit board includes two conductive layers and one insulating layer. Along the thickness direction of the circuit board, the insulating layer is arranged between the two conductive layers.

14. The circuit board assembly according to any one of claims 1 to 13, characterized in that: Each of the interference sources is any one of the following modules: a liquid crystal display module, a camera module or a radio frequency module.

15. An electronic device, characterized in that: Comprising a circuit board assembly as claimed in any one of claims 1-14.

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