Circuit board assembly and electronic equipment

Abstract

The embodiment of the invention provides a circuit board assembly and electronic equipment. The circuit board assembly comprises a circuit board, at least one strong interference structure, at least one disturbed source and at least one electromagnetic band gap structure. The at least one electromagnetic band gap structure is arranged on the circuit board, each electromagnetic band gap structure corresponds to one strong interference structure and one disturbed source, and each electromagnetic band gap structure is used for improving the isolation degree between the corresponding disturbed source and the corresponding strong interference structure. According to the circuit board assembly and the electronic equipment provided by the embodiment of the invention, the isolation degree between the strong interference structure and the disturbed source can be improved, so that the interference of the strong interference structure on the disturbed source is reduced.

Description

Technical Field

[0001] 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

[0002] At present, electronic devices include a circuit board and a radio frequency module arranged on the surface of the circuit board. The circuit board includes a processor, surface wiring, connectors and other devices exposed on the surface of the circuit board. The radio frequency module is used to receive radio frequency signals. However, when transmitting high-frequency clock signals or high-speed digital signals, the processor, surface wiring, connectors and other devices are prone to electromagnetic interference, which affects the reception of radio frequency communication. Therefore, how to avoid electromagnetic interference affecting the reception of radio frequency communication has become a problem that needs to be solved urgently. Summary of the invention

[0003] The embodiments of the present application provide a circuit board assembly and an electronic device, which can improve the isolation between a strong interference structure and an interference source, so as to reduce the interference of the strong interference structure on the interference source.

[0004] In a first aspect, the present application provides a circuit board assembly, including a circuit board, at least one strong interference structure, at least one disturbed source, and at least one electromagnetic bandgap structure. At least one electromagnetic bandgap structure is arranged on the circuit board, each electromagnetic bandgap structure corresponds to a strong interference structure and a disturbed source, and each electromagnetic bandgap structure is used to improve the isolation between the corresponding disturbed source and the corresponding strong interference structure.

[0005] The circuit board assembly provided by the embodiment of the present application is provided with at least one electromagnetic bandgap structure on the circuit board, and each electromagnetic bandgap structure can improve the isolation between the corresponding strong interference structure and the corresponding disturbed source, so that the interference of the strong interference structure on the disturbed source is reduced or even does not interfere. In addition, the electromagnetic bandgap structure does not affect the normal use of the circuit board, and the signal integrity can be taken into account.

[0006] In a possible implementation manner, each electromagnetic band gap structure is disposed near a corresponding strong interference structure.

[0007] The circuit board assembly provided in the embodiment of the present application can convert the electromagnetic waves emitted by each strong interference structure into decay waves (evanescent waves) by setting each electromagnetic band gap structure near the corresponding strong interference structure, and limit the electromagnetic waves emitted by the strong interference structure to a certain range, thereby suppressing the transmission of electromagnetic waves, thereby reducing the coupling degree between the disturbed source and the strong interference structure, and then improving the isolation degree between the disturbed source and the strong interference structure. In addition, suppressing interference at the source end can reduce the difficulty of setting the electromagnetic band gap structure, and can also reduce the difficulty of suppressing interference.

[0008] In a possible implementation manner, along a direction perpendicular to the thickness direction of the circuit board, each electromagnetic bandgap structure is arranged on a side of the corresponding strong interference structure facing the corresponding interference source.

[0009] 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.

[0010] In a possible implementation manner, 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.

[0011] 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 interfered source can be suppressed by the corresponding electromagnetic band gap structure to ensure the performance of the circuit board assembly.

[0012] In a possible implementation manner, 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.

[0013] In a possible implementation, at least one strong interference structure is a surface routing, wherein: when each surface routing corresponds to a plurality of electromagnetic bandgap structures, the plurality of electromagnetic bandgap structures corresponding to each surface routing are arranged on the same side of the surface routing along a direction perpendicular to the direction of the circuit board. Or, when each surface routing corresponds to a plurality of electromagnetic bandgap structures, the plurality of electromagnetic bandgap structures corresponding to each surface routing are arranged on opposite sides of the surface routing along a direction perpendicular to the direction of the circuit board. With such an arrangement, the electromagnetic waves emitted by the surface routing can be converted into falling waves, thereby suppressing the circuit board propagation generated by the surface routing, and further reducing the interference of the surface routing to the disturbed source. In addition, by improving the isolation between the surface routing and the disturbed source through the electromagnetic bandgap structure, not only can the electromagnetic interference of the surface routing to the disturbed source be reduced, but also the interference cost can be reduced.

[0014] 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.

[0015] 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.

[0016] In a possible implementation, along a direction perpendicular to the thickness direction of the circuit board, the electromagnetic band gap structure corresponding to each cavity structure is arranged on a side of the cavity structure facing the interference source corresponding to the electromagnetic band gap structure.

[0017] 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 disturbed source, which can ensure that the near-field electromagnetic waves leaving the cavity structure and moving toward the disturbed source can be converted into falloff waves, thereby suppressing the propagation of near-field electromagnetic waves and improving the isolation between the disturbed source and the cavity structure.

[0018] In a possible implementation, the circuit board assembly further 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 spaced apart. The circuit board and the heat sink are electrically connected and form a cavity structure with the heat sink.

[0019] 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 waves in the cavity structure can be converted into falloff waves 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.

[0020] In a possible implementation, 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.

[0021] 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 interfered source, and can reduce or shield the interference of the strong interference structure on the interfered source.

[0022] In a possible implementation, the metal layer includes a plurality of sub-metal segments, and the electrical connection structure includes a plurality of sub-structures. In 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 sub-structures correspond to the plurality of sub-metal segments one by one, and each sub-structure is electrically connected to the ground layer and the corresponding sub-metal segment.

[0023] 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 sub-structure, so that each electromagnetic band gap structure can be equivalent to a parallel LC resonant circuit with relatively strong local resonance characteristics to increase the resonance performance of the unit, and then the characteristic of infinite reactance when the unit resonates is utilized to prevent the propagation of electromagnetic waves near the resonant frequency to form a frequency band gap, thereby achieving the purpose of improving the isolation between the strong interference structure and the disturbed source.

[0024] In a possible implementation, the circuit board includes at least one insulating layer and at least one conductive layer, wherein: when there is one conductive layer, the number of insulating layers is one, and the conductive layer and the insulating layer are stacked along the thickness direction of the circuit board. Or, when there are multiple conductive layers, an insulating layer is provided between two adjacent conductive layers along the thickness direction of the circuit board.

[0025] 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 band gap structure on the circuit board, the interference of the strong interference structure on the interference source can be reduced.

[0026] In a possible implementation, the circuit board includes two conductive layers and an insulating layer, and along the thickness direction of the circuit board, the insulating layer is disposed between the two conductive layers.

[0027] When the circuit board in the circuit board assembly provided in the embodiment of the present application is a double-layer board, the surface wiring exposed on the surface can be suppressed by the electromagnetic bandgap structure to prevent the surface wiring from interfering with the source of interference. In addition, when the electromagnetic bandgap structure is used to solve the electromagnetic interference problem caused by the surface wiring, there is no need to set up shielding elements such as shielding covers, which can reduce costs.

[0028] In a possible implementation manner, each interfered source is any one of the following modules: a liquid crystal display module, a camera module or a radio frequency module.

[0029] The circuit board assembly provided in the embodiment of the present application can avoid affecting the structure of the RF module, or can avoid screen distortion of the LCD display module, or can avoid camera freeze by setting an electromagnetic band gap structure on the circuit board to improve the isolation between the interfered source and the strong interference structure.

[0030] 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

[0031] Figure 1 This is a schematic diagram of a first structure for reducing interference in the related art;

[0032] Figure 2It is a schematic diagram of a second structure for reducing interference in the related art;

[0033] Figure 3 This is the change diagram of isolation before and after using common mode inductors;

[0034] Figure 4 A schematic diagram of the structure of a first circuit board assembly provided in an embodiment of the present application;

[0035] Figure 5 A schematic diagram of the structure of a second circuit board assembly provided in an embodiment of the present application;

[0036] Figure 6 A schematic diagram of the structure of a third circuit board assembly provided in an embodiment of the present application;

[0037] Figure 7 A schematic structural diagram of a first electromagnetic bandgap structure provided in an embodiment of the present application;

[0038] Figure 8 A schematic diagram of the structure of a second electromagnetic bandgap structure provided in an embodiment of the present application;

[0039] Fig. 9 for Figure 7 Simulation diagram of the electromagnetic bandgap structure shown;

[0040] Fig.10 for Figure 7 The equivalent circuit diagram of the electromagnetic bandgap structure shown;

[0041] Fig.11 for Figure 7 The resonance characteristics diagram of the electromagnetic bandgap structure shown;

[0042] Fig.12 for Figure 7 Frequency diagram of the electromagnetic bandgap structure in ;

[0043] Fig.13 To adopt Figure 7 The isolation effect diagram before and after the electromagnetic bandgap structure is shown;

[0044] Fig.14 for Figure 6 Schematic diagram of the circuit board structure.

[0045] Description of reference numerals:

[0046] 100. Circuit board assembly;

[0047] 10. Circuit board; 11. Insulation layer; 12. Conductive layer;

[0048] 20. Electromagnetic band gap structure; 21. Ground layer; 22. Metal layer; 221. Sub-metal segment; 23. Electrical connection structure; 231. Sub-structure;

[0049] 30. Disturbance source;

[0050] 40. Strong interference structure; 41. Surface routing; 42. Cavity structure;

[0051] 50. Radiator. DETAILED DESCRIPTION

[0052] At present, the clock frequency of terminal products, such as routers, has reached the microwave frequency band. The short traces on chips, modules and printed circuit boards (PCBs) are easily equivalent to antennas, radiating noise into space and being received by radio frequency communications to cause interference. In addition, the usage scenarios involve a large amount of digital signal interaction, transmission and processing in the system. At this time, the transmission of data signals will also interfere with the reception of radio frequency communications, thereby 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.

[0053] Figure 1 This is a schematic diagram of the first structure for reducing interference in the related art. Figure 1 As shown, when the processor 110 and the WIFI module 120 perform data interaction, the 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, so as to achieve the compatibility between digital and radio frequency. Figure 2 This is a schematic diagram of the second structure for reducing interference in the related art, see Figure 2 As shown, try to separate the routing of high-frequency clock signals and high-speed signals (such as Figure 2 140) goes inside, and covers the ground from top to bottom and left to right (as shown in Figure 2 The surface wiring that cannot be routed through the inner layer is also shielded so that it cannot be received by the RF module through spatial radiation. However, these methods all have the problem of increased costs. In addition, the interference treatment through the common mode inductor 130 has little improvement in the isolation of the RF interference suppression of spatial propagation, such as Figure 3 As shown, the use of common mode inductor 130 has only a 2dB actual benefit in improving the isolation of radio frequency interference suppression in space propagation, where: Figure 3 The following is a diagram showing the change in isolation before and after the use of common-mode inductors. Figure 3 In the figure, A represents the isolation change curve without the common mode inductor 130, and B represents the isolation change curve with the common mode inductor 130. In addition, since filtering has frequency characteristics, it can often only be optimized for interference within a certain frequency range. Interference at multiple frequency points requires further increasing the number of common mode inductors 130, resulting in further increase in cost. Therefore, how to solve electromagnetic interference while avoiding new problems has become an urgent problem to be solved.

[0054] In view of this, the embodiment of the present application provides a circuit board assembly 100 and an electronic device, which can improve the isolation between the strong interference structure 40 and the disturbed source 30, so as to reduce the interference of the strong interference structure 40 on the disturbed source 30. For example, when the strong interference structure 40 is a surface wiring 41, in a scenario with a high-frequency clock and / or high-speed data transmission, the interference of the surface wiring 41 on the disturbed source 30 is reduced.

[0055] 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.

[0056] The electronic device provided in the embodiment of the present application may include but is not limited to a router, a television, a mobile phone, a tablet computer, a laptop computer, a desktop computer, a communication device, etc. In the embodiment of the present application, a router is taken as an example for explanation.

[0057] The circuit board assembly 100 provided in the embodiment of the present application is described in detail below with reference to the accompanying drawings.

[0058] Figure 4 This is a schematic diagram of the structure of the first circuit board assembly provided in the embodiment of the present application. Figure 4 As shown, the circuit board assembly 100 provided in the embodiment of the present application includes a circuit board 10, at least one strong interference structure 40, at least one disturbed source 30 and at least one electromagnetic bandgap structure 20. Among them, at least one electromagnetic bandgap structure 20 is arranged on the circuit board 10, each electromagnetic bandgap structure 20 corresponds to a strong interference structure 40 and a disturbed source 30, and each electromagnetic bandgap structure 20 is used to improve the isolation between the corresponding disturbed source 30 and the corresponding strong interference structure 40.

[0059] The strong interference structure 40 refers to a structure that emits electromagnetic waves to interfere with the source 30, and may include but is not limited to vias, chips, surface traces 41, connectors, cavity structures 42, or buckle seats. Figure 4 As shown, the strong interference structure 40 is a surface wiring 41 .

[0060] There is no limitation on the specific number of the strong interference structures 40. Figure 4 As shown, 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.

[0061] There is no limitation on the specific number of the disturbed sources 30. Figure 4As shown, the number of the disturbed source 30 is one. Of course, in some embodiments, the number of the disturbed source 30 may also be multiple. When the number of the disturbed source 30 is multiple, the number of the electromagnetic bandgap structures 20 corresponding to each disturbed source 30 may be the same or different.

[0062] 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. Among them, in the embodiment of the present application, the radio frequency module is taken as the above-mentioned disturbed source 30 as an example for explanation, and 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 to 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, which can reduce the interference of the strong interference structure 40 to the camera module, and can 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 to the liquid crystal display, and avoid the problem of flower screen in the liquid crystal display module.

[0063] There is no limitation on the specific number of the electromagnetic bandgap structures 20, and for example, the number may include but is not limited to one, two, three, four, five, etc. For example, Figure 4 As shown, the number of the EBG structures 20 is four.

[0064] In the embodiment of the present application, by setting 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 disturbed source 30, and each electromagnetic bandgap structure 20 can improve the isolation between the corresponding strong interference structure 40 and the corresponding disturbed source 30, so as to reduce the interference of the strong interference structure 40 to the disturbed source 30. In addition, reducing the interference of the strong interference structure 40 to the disturbed source 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, setting 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 the use requirements.

[0065] In the embodiment of the present application, the electromagnetic bandgap structure 20 (EBG) can form a high impedance surface to convert the electromagnetic waves interfering with the disturbed source 30 into decaying waves (evanescent waves), so that the disturbed source 30 will not be affected by electromagnetic interference, thereby improving the isolation between the disturbed source 30 and the strong interference structure 40.

[0066] Continue to see Figure 4 As shown, each EBG structure 20 is disposed near a corresponding strong interference structure 40 .

[0067] Of course, in some possible implementations, each electromagnetic bandgap structure 20 may also be disposed near the corresponding disturbed source 30 (not shown in the figure). Alternatively, in some possible implementations, along a direction perpendicular to the thickness direction of the circuit board 10, each electromagnetic bandgap structure 20 may also be disposed in the middle of the corresponding disturbed source 30 and the corresponding strong interference structure 40 (not shown in the figure).

[0068] Accordingly, each electromagnetic band gap structure 20 is arranged near the corresponding strong interference structure 40 or near the corresponding disturbed source 30 or in the middle of the corresponding strong interference structure 40 and the disturbed source 30, which can improve the isolation between the disturbed source 30 and the strong interference structure 40. However, by arranging each electromagnetic band gap structure 20 near the corresponding strong interference structure 40, interference can be suppressed at the source end, which can reduce the difficulty of arranging the electromagnetic band gap structure 20 and the difficulty of suppressing interference.

[0069] Continue to see Figure 4 As shown, by arranging each electromagnetic band gap structure 20 near the corresponding strong interference structure 40, 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.

[0070] Each electromagnetic band gap structure 20 is arranged near the corresponding strong interference structure 40 or near the corresponding disturbed source 30. The vicinity can be understood as: 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 at intervals with the corresponding strong interference structure 40 or the corresponding disturbed source 30 (such as Figure 4 As shown), or each electromagnetic band gap structure 20 may also be arranged side by side and in contact with the corresponding strong interference structure 40 or the corresponding source of interference 30, or the projection of each electromagnetic band gap structure 20 along the thickness direction of the circuit board 10 partially overlaps with the projection of the corresponding strong interference structure 40 or the projection of the corresponding source of interference 30. In other words, along the direction perpendicular to the thickness direction of the circuit board 10, nearby may mean that the spacing between each electromagnetic band gap structure 20 and the corresponding source of interference 30 and the corresponding strong interference structure 40 is smaller than the spacing between the other, for example Figure 4As shown, each EBG structure 20 is disposed near a corresponding strong interference structure 40 , and the distance between the strong interference structure 40 and the EBG structure 20 is smaller than the distance between the disturbed source 30 and the EBG structure 20 .

[0071] In some possible implementations, see Figure 4 As shown, along the direction perpendicular to the thickness direction of the circuit board 10, each electromagnetic band gap structure 20 can be arranged on the side of the corresponding strong interference structure 40 facing the corresponding disturbed source 30. Accordingly, each electromagnetic band gap structure 20 is arranged on the transmission path between the corresponding strong interference structure 40 and the disturbed source 30, and the electromagnetic wave emitted by the strong interference structure 40 and moving toward the disturbed source 30 can be converted into a falloff wave to reduce interference.

[0072] 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 .

[0073] 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.

[0074] Figure 5 The schematic diagram of the structure of the second circuit board assembly provided in the embodiment of the present application is as follows. In a possible implementation, the circuit board assembly 100 may include a plurality of strong interference structures 40, such as Figure 5 As shown, the circuit board assembly 100 includes two strong interference structures 40. Of course, the specific number of the strong interference structures 40 is not limited to two. Each strong interference structure 40 of at least one strong interference structure 40 in the multiple strong interference structures 40 corresponds to at least one electromagnetic band gap structure 20. In some embodiments, a part of the multiple strong interference structures 40 of the circuit board assembly 100 may correspond to the electromagnetic band gap structure 20, and another part may not correspond to the electromagnetic band gap structure 20, for example Figure 5 As shown, one strong interference structure 40 corresponds to four electromagnetic band gap structures 20, and another strong interference structure 40 does not correspond to an electromagnetic band gap structure 20. Or 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 is used to improve the isolation between the strong interference structure 40 that interferes with the disturbed source 30 and the disturbed source 30, thereby reducing the interference to the disturbed element 30.

[0075] 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.

[0076] 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.

[0077] In the embodiment of the present application, since each strong interference structure 40 may include but is not limited to a via, a surface wiring 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 wirings 41. Or in one embodiment, the multiple strong interference structures 40 include surface wirings 41 and cavity structures 42. Or in one embodiment, the multiple strong interference structures 40 include surface wirings 41, cavity structures 42 and vias.

[0078] 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 the three strong interference structures 40 is a surface trace 41, or the three strong interference structures 40 may all be surface traces 41. When each surface trace 41 corresponds to a plurality of electromagnetic band gap structures 20, along a direction perpendicular to the direction of the circuit board 10, the plurality of electromagnetic band gap structures 20 corresponding to each surface trace 41 are arranged on the same side of the surface trace 41, for example Figure 4 shown.

[0079] 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 a plurality of electromagnetic band gap structures 20, the plurality of electromagnetic band gap structures 20 corresponding to each surface trace 41 are arranged 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.

[0080] In summary, the multiple electromagnetic bandgap structures 20 corresponding to each surface wiring 41 are arranged on the same side or opposite sides of the surface wiring 41, and the electromagnetic waves emitted by the surface wiring 41 can be converted into decay waves, thereby suppressing the propagation of the circuit board 10 generated by the surface wiring 41, and further reducing the interference of the surface wiring 41 to the disturbed source 30. In addition, the isolation between the surface wiring 41 and the disturbed source 30 is improved by the electromagnetic bandgap structure 20, which can not only reduce the electromagnetic interference of the surface wiring 41 to the disturbed source 30, but also reduce the interference cost.

[0081] Figure 6 This is a schematic diagram of the structure of the 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 Figure 6 As shown, 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 can also be two or three. The electromagnetic bandgap structure 20 corresponding to each cavity structure 42 is arranged at the edge of the cavity structure 42.

[0082] 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.

[0083] 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 .

[0084] The principle of the cavity structure 42 interfering 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 leaving the cavity structure 42 has become a falloff wave, the amplitude of the electromagnetic wave will not decay 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, which can suppress the propagation of the near-field electromagnetic wave.

[0085] 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 arranged inside the cavity structure 42, or the cavity structure 42 can also be arranged between the interference source 30 and at least one of the remaining strong interference structures 40.

[0086] In some embodiments, see Figure 6 As shown, at least a portion of each electromagnetic band gap structure 20 of at least one electromagnetic band gap structure 20 corresponding to each cavity structure 42 may be disposed inside the cavity defined by the cavity structure 42. In other words, along the thickness direction of the circuit board 10, the projection of the electromagnetic band gap structure 20 corresponding to each cavity structure 42 at least partially overlaps with the projection of the cavity structure 42.

[0087] Alternatively, in some embodiments, each electromagnetic band gap structure 20 of at least one electromagnetic band gap structure 20 corresponding to each cavity structure 42 may also be disposed outside the cavity defined by the cavity structure 42 (not shown in the figure). In other words, along the thickness direction of the circuit board 10, the projection of the electromagnetic band gap structure 20 corresponding to each cavity structure 42 does not overlap with the projection of the cavity structure 42.

[0088] Continue to see Figure 6 As shown, along the direction perpendicular to the thickness direction of the circuit board 10, the electromagnetic band gap structure 20 corresponding to each cavity structure 42 is arranged on the side of the cavity structure 42 facing the disturbed source 30 corresponding to the electromagnetic band gap structure 20. Such an arrangement can ensure that the near-field electromagnetic wave leaving the cavity structure 42 and heading toward the disturbed source 30 can be converted into a falloff wave, suppressing the propagation of the near-field electromagnetic wave, so as to improve the isolation between the cavity structure 42 and the disturbed source 30.

[0089] 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 along 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.

[0090] 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.

[0091] In some embodiments, see Figure 6 As shown, the circuit board assembly 100 may also include a heat sink 50. Among them, along the thickness direction of the circuit board 10, the circuit board 10 and the heat sink 50 are arranged side by side and spaced apart, and the circuit board 10 is electrically connected to the heat sink 50 and surrounds a cavity structure 42 with the heat sink 50. Accordingly, when the heat sink 50 and the circuit board 10 surround the cavity structure 42, the electromagnetic band gap structure 20 arranged at the edge of the cavity structure 42 can convert the near-field propagation wave in the cavity structure 42 into a falloff wave, suppress the propagation of the near-field electromagnetic wave, reduce the spatial coupling, and thus improve the isolation between the strong interference structure 40 and the disturbed source 30.

[0092] In which, along the thickness direction of the circuit board 10, the projection of the heat sink 50 may 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.

[0093] 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 that the operating temperature of the heating device is within a reasonable range. The heating device may include but is not limited to a chip, storage, etc.

[0094] There is no limitation on the specific structure of the heat sink 50. For example, the heat sink 50 includes a main body and a plurality of plate-like parts, wherein the plurality of plate-like parts are arranged on a first side of the main body, and the second side of the main body is used to face the heating device, and the first side and the second side are arranged opposite to each other along the thickness direction of the circuit board 10.

[0095] In some embodiments, the circuit board assembly 100 may further include a metal sheet (not shown in the figure). In which, along the thickness direction of the circuit board 10, the circuit board 10 and the metal sheet are arranged side by side and spaced apart, and 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 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 falloff wave, suppress the propagation of the near-field electromagnetic wave, reduce the spatial coupling, and improve the isolation between the strong interference structure 40 and the disturbed source 30.

[0096] 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.

[0097] 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 exists alone.

[0098] Figure 7 The schematic diagram of the structure of the first electromagnetic bandgap structure provided in the embodiment of the present application. In some possible implementations, combined with the above Figure 6 , and see Figure 7As shown, each electromagnetic bandgap structure 20 includes a ground layer 21, a metal layer 22 and an electrical connection structure 23. In 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 the electromagnetic bandgap structure 20 with such a structure, 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 to the interfered source 30 can be reduced or shielded.

[0099] 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.

[0100] See also Figure 7 As shown, the metal layer 22 may include a plurality of sub-metal segments 221, and the electrical connection structure 23 includes a plurality of sub-structures 231. The plurality of sub-metal segments 221 are arranged side by side and at intervals along a direction perpendicular to the thickness direction of the circuit board 10. The plurality of sub-structures 231 correspond to the plurality of sub-metal segments 221 one by one, and each sub-structure 231 is electrically connected to the ground layer 21 and the corresponding sub-metal segment 221.

[0101] 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 bandgap structure 20 is in the shape of an “I”, for example Figure 8 As shown, Figure 8 A schematic structural diagram of a second electromagnetic bandgap structure provided in an embodiment of the present application.

[0102] 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 to reduce interference. However, the metal layer 22 is composed of multiple sub-metal segments 221, which can further improve the effect of reducing interference.

[0103] Fig. 9 for Figure 7 The simulation diagram of the electromagnetic bandgap structure shown in the figure, Fig.10 for Figure 7 The equivalent circuit diagram of the electromagnetic bandgap structure shown in Fig.11 for Figure 7 The resonance characteristics of the electromagnetic bandgap structure shown in the figure, Fig.12 for Figure 7 The frequency diagram of the electromagnetic bandgap structure in Figure 7 , and see Fig. 9 As shown, the electromagnetic bandgap structure 20 can be equivalent to a parallel LC resonant circuit with relatively strong local resonance characteristics (such as Fig.10 ) to increase the resonance performance of the electromagnetic bandgap structure 20. Then, the characteristic of infinite reactance when the electromagnetic bandgap structure 20 resonates (as shown in FIG. Fig.11 As shown), preventing the resonant frequency (as Fig.11 As shown, the electromagnetic wave propagates near the resonant frequency of 5.28 GHz to form a frequency band gap (as shown in Fig.12 shown).

[0104] In addition, the electromagnetic bandgap structure 20 is a periodic structure with a band-stop characteristic, which provides a low-impedance path for high-frequency current (or noise) between the two planes. The two reference planes are short-circuited in AC, which makes the noise generated by the interference source plane quickly form a loop through the local low-impedance path and cannot propagate outward, thereby achieving the effect of noise suppression.

[0105] In addition, while noise is suppressed, electromagnetic radiation is also reduced. The electromagnetic bandgap structure 20, which can be designed as a special form for high-frequency current or noise between two planes, can suppress electromagnetic waves of a specific frequency generated on the high-speed circuit board 10. When the high-speed circuit board 10 is working, the electromagnetic waves generated by intermittent or continuous voltage and current changes pass through the electromagnetic bandgap structure 20 designed to a specific frequency, and a resonant circuit is generated to suppress the propagation of electromagnetic waves at the resonant frequency, thereby achieving the purpose of reducing interference.

[0106] Fig.13 To adopt Figure 7 The isolation effect diagram before and after the electromagnetic bandgap structure is shown in FIG. Figure 7 The isolation curve of the electromagnetic bandgap structure shown in the figure is that D is not used. Figure 7 The isolation curve of the electromagnetic bandgap structure is shown in Figure 1. Fig.13 It can be seen that by providing the electromagnetic bandgap structure 20 on the circuit board 10 , the isolation between the strong interference structure 40 and the interference source 30 can be improved.

[0107] Fig.14 for Figure 6 See the schematic diagram of the circuit board in Fig.14 As shown, the circuit board 10 includes at least one insulating layer 11 and at least one conductive layer 12. Fig.14 Insulating layer 11 and conductive layer 12 are stacked.

[0108] There is no limitation on the specific number of the conductive layers 12 and the specific number of the insulating layers 11. In one embodiment, when there is one conductive layer 12, the number of the insulating layer 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 arranged 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 arranging the electromagnetic bandgap structure 20 on the circuit board 10, the interference of the strong interference structure 40 on the disturbed source 30 can be reduced.

[0109] In the embodiment of the present application, the two-layer board is taken as the above-mentioned circuit board 10 as an example for explanation. Fig.14 As shown, the two-layer board includes two conductive layers 12 and an insulating layer 11 . Along the thickness direction of the circuit board 10 , the insulating layer 11 is disposed between the two conductive layers 12 .

[0110] Since the circuit board 10 is a two-layer board, the wiring of the circuit board 10 is exposed (such as Figure 6 As shown), 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 disturbed source 30. If a shielding cover or other structure is used to reduce the interference of the surface wiring 41 on the disturbed 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, so that the overall benefit is 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 disturbed source 30 be improved, but also the shielding cost is much less than the cost benefit of using a single-layer board or a double-layer board, so that the overall benefit is 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 disturbed source 30 is improved by the electromagnetic bandgap structure 20, which can not only reduce the interference of the strong interference structure 40 on the disturbed source 30, but also reduce the cost without adding an electromagnetic interference shielding cover.

[0111] Continue to see Figure 6 As shown, since the circuit board 10 is a two-layer board, the metal layer 22 and the grounding layer 21 of each electromagnetic bandgap structure 20 can be respectively arranged on opposite sides of the insulating layer 11, and the grounding 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. Or in some embodiments, the grounding layer 21 can be an integral structure with one of the two conductive layers 12 of the circuit board 10, such as Figure 6As shown, in other words, the ground layer 21 of each electromagnetic bandgap structure 20 is a part of a conductive layer 12 of the circuit board 10 .

[0112] It should be noted that, in addition to improving the isolation between the strong interference structure 40 and the disturbed source 30, the electromagnetic band gap structure 20 can also be used as an isolation structure to improve the isolation between antennas, and the resonant frequency can be designed according to the requirements. In addition, the electromagnetic band gap structure 20 can also be used to reduce the impact of electromagnetic emissions such as radio, millimeter waves, and infrared on digital signals.

[0113] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0114] In the embodiments of the present application, the devices or elements referred to or implied must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present application. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise precisely and specifically specified.

[0115] 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 sequence. 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 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.

[0116] The term "plurality" in this article refers to two or more than two. The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the previous and next associated objects are in an "or" relationship; in a formula, the character " / " indicates that the previous and next associated objects are in a "division" relationship.

[0117] It should be understood that the various numerical numbers involved in the embodiments of the present application are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application.

[0118] 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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