Filter, circuit board and electronic equipment

Abstract

The invention discloses a filter, a circuit board and electronic equipment, and aims to reduce the size of the filter. According to the filter provided by the embodiment of the invention, the filtering groove and the communication groove can be arranged on the wiring layer or the filtering layer, and can also be arranged on the wiring layer and the filtering layer at the same time, the extension direction of the filtering groove is parallel to the signal line, one end of the filtering groove is communicated with the wiring groove through the communication groove, and the hysteresis structure is arranged in the filtering groove. The slow wave structure can reduce the propagation speed of the first noise electromagnetic wave in the filtering groove so as to reduce the length required by the filtering groove and further reduce the size of the filter.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of signal transmission technology, and specifically to a filter, a circuit board, and an electronic device. Background Art

[0002] The circuit board includes two signal lines for transmitting differential signals and a filter layer. The filter layer is provided with a groove extending perpendicular to the signal lines and a filter slot connected to the groove at one end. The filter slot extends parallel to the signal lines. When the two signal lines transmit signals, they generate noise electromagnetic waves. After the noise electromagnetic waves enter the filter slot, they form reflected electromagnetic waves. The reflected electromagnetic waves are 180° out of phase with the noise electromagnetic waves, thereby eliminating the influence of the noise electromagnetic waves and achieving filtering. To ensure a 180° phase difference between the reflected electromagnetic waves and the noise electromagnetic waves, the length of the filter slot parallel to the signal lines is 1 / 4 of the wavelength of the noise electromagnetic waves, resulting in a long filter slot. Summary of the Invention

[0003] Embodiments of the present application provide a filter, a circuit board, and an electronic device, aiming to reduce the size of the filter.

[0004] On the one hand, an embodiment of the present application provides a filter, including a routing layer, a filter layer and a hysteresis wave structure, a routing groove is provided in the routing layer, a signal line is provided in the routing groove, the filter layer and the routing layer are stacked, a filter groove and a connecting groove are provided on the filter layer and / or the routing layer, the extension direction of the filter groove is parallel to the signal line, one end of the filter groove is connected to the routing groove through the connecting groove, the hysteresis wave structure is provided in the filter groove, and the hysteresis wave structure is used to reduce the propagation speed of the first noise electromagnetic wave in the filter groove.

[0005] In the filter provided in the embodiment of the present application, the filter slot and the connecting slot can be arranged on the routing layer or the filtering layer, or can be arranged on the routing layer and the filtering layer at the same time. The extension direction of the filter slot is parallel to the signal line, and one end of the filter slot is connected to the routing slot through the connecting slot. The hysteresis wave structure is arranged in the filter slot. The hysteresis wave structure can reduce the propagation speed of the first noise electromagnetic wave in the filter slot, so as to reduce the required length of the filter slot and thereby reduce the size of the filter.

[0006] In an embodiment of the present application, the filter slot includes a first filter slot, the connecting slot includes a first connecting slot, the first filter slot and the first connecting slot are both arranged on the routing layer, and the first filter slot is connected to the routing slot through the first connecting slot; the hysteresis wave structure includes a first hysteresis wave structure, and the first hysteresis wave structure is arranged in the first filter slot.

[0007] Through the above arrangement, the first noise electromagnetic wave generated by the signal line can enter the first filter slot through the first connecting slot connected to the routing slot and form a reflected electromagnetic wave in the first filter slot, thereby filtering the first noise electromagnetic wave; the first hysteresis structure can reduce the propagation speed of the first noise electromagnetic wave in the first filter slot, thereby reducing the required length of the first filter slot and further reducing the size of the filter.

[0008] In an embodiment of the present application, the filter layer also includes a first filter layer, the routing layer and the first filter layer are stacked, the filter slot also includes a second filter slot, the connecting slot also includes a second connecting slot, the second filter slot and the second connecting slot are both arranged on the first filter layer, and the second filter slot is connected to the routing slot through the second connecting slot; the hysteresis wave structure also includes a second hysteresis wave structure, and the second hysteresis wave structure is arranged in the second filter slot.

[0009] Through the above arrangement, the first noise electromagnetic wave generated by the signal line can enter the second filter slot through the second connecting slot connected to the routing slot, and form a reflected electromagnetic wave in the second filter slot, thereby filtering the first noise electromagnetic wave; the second hysteresis structure can reduce the propagation speed of the first noise electromagnetic wave in the second filter slot, thereby reducing the required length of the second filter slot and further reducing the size of the filter.

[0010] In an embodiment of the present application, the filter layer also includes a second filter layer, the routing layer is stacked between the first filter layer and the second filter layer, the filter slot also includes a third filter slot, the connecting slot also includes a third connecting slot, the third filter slot and the third connecting slot are both arranged on the second filter layer, and the third filter slot is connected to the routing slot through the third connecting slot; the hysteresis wave structure also includes a third hysteresis wave structure, and the third hysteresis wave structure is arranged in the third filter slot.

[0011] Through the above arrangement, the first noise electromagnetic wave generated by the signal line can enter the third filter slot through the third connecting slot connected to the routing slot, and form a reflected electromagnetic wave in the third filter slot, thereby filtering the first noise electromagnetic wave; the third hysteresis structure can reduce the propagation speed of the first noise electromagnetic wave in the third filter slot, thereby reducing the required length of the third filter slot and further reducing the size of the filter.

[0012] In the embodiment of the present application, in a plane parallel to the routing layer, the projection of the first filter slot and the projection of the second filter slot at least partially overlap, so that the first filter slot and the second filter slot can be connected to improve the filtering effect of the first noise electromagnetic wave.

[0013] In the embodiment of the present application, in a plane parallel to the routing layer, the projection of the first filter slot and the projection of the third filter slot at least partially overlap, so that the first filter slot and the third filter slot can be connected to improve the filtering effect of the first noise electromagnetic wave.

[0014] In an embodiment of the present application, the filter further includes a shielding layer, which is stacked with a routing layer, the filter layer is located between the shielding layer and the routing layer, and the shielding layer is configured to be grounded.

[0015] Through the above arrangement, the first noise electromagnetic wave emitted by the signal line located in the routing layer tends to radiate toward the shielding layer, which facilitates the transmission of the first noise electromagnetic wave in the filter slot provided on the filter layer.

[0016] In an embodiment of the present application, the filter also includes a metal defect layer, which is stacked between the routing layer and the shielding layer, and a cavity is provided in the metal defect layer; in a plane parallel to the routing layer, the projection of the cavity and the projection of the filter groove at least partially overlap.

[0017] Through the above setting, during the radiation of the first noise electromagnetic wave, the cavity in the metal defect layer increases the distance between the routing layer and the shielding layer, which can increase the band rejection of the first noise electromagnetic wave and improve the filtering effect of the filter on the first noise electromagnetic wave.

[0018] In an embodiment of the present application, the hysteresis structure includes multiple hysteresis grooves, which are arranged at equal intervals along the length direction of the filter groove. The hysteresis grooves extend in a direction parallel to the routing layer, and the hysteresis groove is connected to the filter groove at one end close to the filter groove.

[0019] With this arrangement, the multiple hysteresis slots form a periodically varying structure along the length of the filter slot, resulting in a periodic change in the dielectric constant of the filter slot along its length. This causes a phase delay in the first noise electromagnetic wave as it propagates within the filter slot, thereby reducing its propagation speed and wavelength. For first noise electromagnetic waves of the same frequency, this reduced wavelength can reduce the required length of the filter slot, thereby reducing the size of the filter.

[0020] In the embodiment of the present application, the extension direction of the hysteresis groove is perpendicular to the extension direction of the signal line, so that the hysteresis groove and the filter groove are more compact, thereby reducing the occupied area of ​​the entire filter.

[0021] In the embodiment of the present application, the hysteresis slot includes a plurality of hysteresis sub-slots, and the plurality of hysteresis sub-slots are arranged on a side of the filter slot close to the signal line and / or on a side of the filter slot far from the signal line.

[0022] Through the above arrangement, the hysteresis slot includes a plurality of hysteresis sub-slots, and the plurality of hysteresis sub-slots can also form a periodically changing structure, which can further reduce the propagation speed of the first noise electromagnetic wave in the filter slot, thereby further reducing the wavelength of the first noise electromagnetic wave and reducing the size of the filter.

[0023] In an embodiment of the present application, the hysteresis trough also includes a first trough body and a second trough body. The first trough body extends in a direction parallel to the routing layer and perpendicular to the signal line, and the second trough body extends in a direction parallel to the routing layer and the signal line. The second trough body is connected to the filter trough through the first trough body.

[0024] Through the above-mentioned arrangement, the way in which the first slot body and the second slot body are connected can extend the length of the hysteresis slot, improve the effect of multiple hysteresis slots in reducing the propagation speed of the first noise electromagnetic wave in the filter slot, further reduce the wavelength of the first noise electromagnetic wave, thereby reducing the required length of the filter slot and further reducing the size of the filter.

[0025] In an embodiment of the present application, the hysteresis trough also includes a third trough body and a fourth trough body. The third trough body extends in a direction parallel to the routing layer and perpendicular to the signal line. The fourth trough body extends in a direction parallel to the routing layer and the signal line. The fourth trough body is connected to the filtering trough through the third trough body. The third trough body and the fourth trough body are located in the area surrounded by the first trough body, the second trough body and the filtering trough.

[0026] Through the above arrangement, the third and fourth slot bodies increase the number of periodically changing structures connected to the filter slot, which can further reduce the propagation speed of the first noise electromagnetic wave in the filter slot, thereby further reducing the wavelength of the first noise electromagnetic wave and reducing the size of the filter.

[0027] In an embodiment of the present application, the hysteresis wave structure includes a plurality of hysteresis wave connecting grooves, the filter groove includes a plurality of filter sub-grooves arranged at intervals, the plurality of filter sub-grooves are located on the same straight line parallel to the signal line, a hysteresis wave connecting groove is provided between adjacent filter sub-grooves, and the sub-grooves are connected through the hysteresis wave connecting groove; the hysteresis wave connecting groove is bent or curved relative to the filter sub-grooves.

[0028] Through the above arrangement, since the hysteresis connecting groove is bent or bent relative to the filter sub-groove, the length of the filter groove including multiple filter sub-grooves (that is, the distance between the end of the filter sub-groove closest to the connecting groove that is connected to the connecting groove and the end of the filter sub-groove farthest from the connecting groove that is farthest from the connecting groove) is less than 1 / 4 times the wavelength of the first noise electromagnetic wave, thereby reducing the required length of the filter groove and thereby reducing the size of the filter.

[0029] In an embodiment of the present application, the hysteresis connecting groove includes a first section and a second section, the first section extends in a direction parallel to the routing layer and perpendicular to the signal line, the second section extends in a direction parallel to the routing layer and the signal line, and the second section is connected to the filter sub-groove through a first section, and / or is connected to another first section through a first section.

[0030] Through the above setting, multiple first sections and multiple second sections can increase the length of the hysteresis connecting groove. It can be understood that the longer the length of the hysteresis connecting groove is, the more the length of the filter groove is reduced, and thus the more the size of the filter is reduced.

[0031] In an embodiment of the present application, the filter also includes an auxiliary filter slot and an auxiliary hysteresis wave structure. The auxiliary filter slot is arranged on the same layer as the filter slot. The length of the auxiliary filter slot is different from that of the filter slot. The extension direction of the auxiliary filter slot is parallel to the signal line. The auxiliary filter slot is connected to the connecting slot. The auxiliary hysteresis wave structure is arranged in the auxiliary filter slot. The auxiliary hysteresis wave structure is used to reduce the propagation speed of the second noise electromagnetic wave in the auxiliary filter slot. The frequencies of the first noise electromagnetic wave and the second noise electromagnetic wave are different.

[0032] Through the above arrangement, the auxiliary filter slot is of different length from the filter slot to achieve filtering of the second noise electromagnetic wave; the auxiliary filter slot extends in a direction parallel to the signal line to make the overall structure of the filter more compact; the auxiliary hysteresis structure can reduce the propagation speed of the second noise electromagnetic wave in the auxiliary filter slot, thereby reducing the required length of the auxiliary filter slot and thereby reducing the size of the filter.

[0033] In an embodiment of the present application, the auxiliary filter slot and the filter slot are located on the same straight line parallel to the signal line, and the connecting slot is located between the auxiliary filter slot and the filter slot, so that the auxiliary filter slot and the filter slot can share the same connecting slot, thereby simplifying the structure of the filter and facilitating reduction in the size of the filter.

[0034] On the other hand, an embodiment of the present application further provides a circuit board, which includes a signal line and the above-mentioned filter, and the signal line is located in a wiring groove of the filter.

[0035] On the other hand, an embodiment of the present application further provides an electronic device, which includes the above-mentioned circuit board.

[0036] It can be understood that the beneficial effects that can be achieved by the circuit board and electronic device provided in the above embodiments of the present application can refer to the beneficial effects of the filter mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] To more clearly illustrate the technical solutions of this application, the following briefly introduces the drawings required for use in some embodiments of this application. Obviously, the drawings described below are only drawings of some embodiments of this application, and those skilled in the art can also derive other drawings based on these drawings. Furthermore, the drawings described below are schematic diagrams and are not intended to limit the actual dimensions of the products, actual processes of the methods, actual timing of signals, and the like involved in the embodiments of this application.

[0038] Figure 1 This is the time domain waveform diagram of common mode noise;

[0039] Figure 2 It is a structural diagram of a defective common mode filter in the related art;

[0040] Figure 3 is the differential mode electric field pattern formed during differential signal transmission;

[0041] Figure 4 is the common-mode electric field pattern formed during differential signal transmission;

[0042] Figure 5 Schematic diagram of the relationship between the differential mode insertion loss and common mode insertion loss of the defective ground structure to electromagnetic waves and the frequency of the electromagnetic waves;

[0043] Figure 6 This is the frequency domain waveform diagram of common mode noise;

[0044] Figure 7 A schematic diagram of the relationship between the common-mode insertion loss of a defective common-mode filter for electromagnetic waves and the frequency of the electromagnetic waves in the related art;

[0045] Figure 8 Schematic diagram of the multi-layer structure of the filter in the embodiment of the present application;

[0046] Figure 9 This is a top view of the wiring layer in the embodiment of the present application. Figure 1 ;

[0047] Figure 10 This is a top view of the wiring layer in the embodiment of the present application. Figure 2 ;

[0048] Figure 11 This is a top view of the wiring layer in the embodiment of the present application. Figure 3 ;

[0049] Figure 12 This is a top view of the wiring layer in the embodiment of the present application. Figure 4 ;

[0050] Figure 13 This is a top view of the wiring layer in the embodiment of the present application. Figure 5 ;

[0051] Figure 14 Comparison of the common mode insertion loss of electromagnetic waves formed in the embodiment of the present application and the common mode insertion loss of electromagnetic waves formed in the prior art Figure 1 ;

[0052] Figure 15 This is a top view of the wiring layer in the embodiment of the present application. Figure 6 ;

[0053] Figure 16 This is a top view of the wiring layer in the embodiment of the present application. Figure 7 ;

[0054] Figure 17Comparison of the common mode insertion loss of electromagnetic waves formed in the embodiment of the present application and the common mode insertion loss of electromagnetic waves formed in the prior art Figure 2 ;

[0055] Figure 18 This is a top view of the filter layer in the embodiment of the present application. Figure 1 ;

[0056] Figure 19 This is a top view of the filter layer in the embodiment of the present application. Figure 2 ;

[0057] Figure 20 This is a top view of the filter layer in the embodiment of the present application. Figure 3 ;

[0058] Figure 21 This is a top view of the filter layer in the embodiment of the present application. Figure 4 ;

[0059] Figure 22 This is a top view of the filter layer in the embodiment of the present application. Figure 5 ;

[0060] Figure 23 This is a top view of the filter layer in the embodiment of the present application. Figure 6 ;

[0061] Figure 24 This is a schematic top view of a metal defect layer in an embodiment of the present application;

[0062] Figure 25 Comparison of the common mode insertion loss of electromagnetic waves formed in the embodiment of the present application and the common mode insertion loss of electromagnetic waves formed in the prior art Figure 3 ;

[0063] Figure 26 Schematic diagram of the structure of the auxiliary filter tank and the auxiliary hysteresis structure in the embodiment of the present application.

[0064] Explanation of the reference numerals: 1. defective ground common mode filter; 2. defective ground structure; 3. defective ground groove; 4. defective ground filter groove; 5. signal line; 6. filter; 7. routing layer; 8. filter layer; 9. routing groove; 10. filter groove; 11. connecting groove; 12. hysteresis structure; 13. hysteresis groove; 14. hysteresis sub-groove; 15. first groove body; 16. second groove body; 17. third groove body; 18. fourth groove body; 19. filter sub-groove; 20. hysteresis connecting groove; 21. first section; 22. second section; 23. first Filter slot; 24, first connecting slot; 25, first hysteresis structure; 26, first filter layer; 27, second filter slot; 28, second connecting slot; 29, second hysteresis structure; 30, second filter layer; 31, third filter slot; 32, third connecting slot; 33, third hysteresis structure; 34, shielding layer; 35, first shielding layer; 36, second shielding layer; 37, metal defect layer; 38, cavity; 39, first metal defect layer; 40, second metal defect layer; 41, auxiliary filter slot; 42, auxiliary hysteresis structure. DETAILED DESCRIPTION

[0065] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0066] In the following, the terms "first," "second," etc. are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the quantity of the technical features indicated. Therefore, a feature specified as "first," "second," etc. may explicitly or implicitly include one or more of the features.

[0067] In addition, in the embodiments of the present application, directional terms such as "up", "down", "left", "right", "horizontal" and "vertical" are defined relative to the orientation of the components in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they can change accordingly according to changes in the orientation of the components in the drawings.

[0068] In the embodiments of the present application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integrated connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0069] It should be noted that, in the description of the embodiments of the present application, unless otherwise clearly specified or limited, the terms "connected" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or an integral connection; it can also be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be a communication between two components. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0070] The present application provides an electronic device, which may include a data storage device or a computer, etc. In some implementations, signal transmission between various devices inside the electronic device and signal transmission between multiple electronic devices can be achieved through signal lines. Among them, the signal line refers to a line used to transmit sensing information and control information in an electrical control circuit. The signal line can be a bundle or multiple bundles of transmission lines composed of multiple cables, or it can be a printed line arranged in a circuit board. In an embodiment where the signal line is a printed line, the electronic device may include a circuit board, and the circuit board may include a printed circuit board (PCB) or a package substrate (Package Substrate), etc. In some embodiments, the circuit board may include multiple signal lines, and the corresponding two signal lines may be arranged adjacent to each other, and the routing distance from the input end to the output end of the two signal lines is roughly the same to achieve differential signal transmission. Differential signal transmission transmits signals on both lines, and the two signals have the same amplitude and opposite phase. The signal receiving end compares the difference between the two voltages to determine the logical state sent by the sending end. Please refer to Figure 1 During the signal transmission process of a pair of signal lines, at the same time, one signal line is configured as positive level P (positive) and the other signal line is configured as negative level N (negative). During the differential signal transmission process, clock offset and other conditions may occur, causing PN imbalance between the two signal lines, thereby generating common mode noise (such as Figure 1 The mid-dotted line indicates the signal transmission, thereby causing electromagnetic interference (EMI) to the signal transmission.

[0071] In the related art, a shielding structure can be set around the signal line to reduce the impact of common mode noise, but this will increase the manufacturing cost of the electronic device. It is also possible to reduce the impact of common mode noise by forming a common mode filter on the circuit board. Figure 2The defective ground common mode filter 1 includes a defective ground structure 2 (Defected Ground Structure), the defective ground structure 2 includes a defective ground groove 3 and a defective ground filter groove 4 connected to the defective ground groove 3, and the extension direction of the defective ground groove 3 is perpendicular to the extension direction of the signal line 5. Please refer to Figure 3 、 Figure 4 and Figure 5 , Figure 3 and Figure 4 They are all cross-sectional views perpendicular to the direction of the signal line 5. Figure 3 is the differential mode electric field pattern formed during differential signal transmission. Figure 4 is the common mode electric field pattern formed during differential signal transmission, Figure 5 is the differential mode insertion loss L1 and common mode insertion loss L2 of the defective ground structure 2 to the electromagnetic wave; it can be understood that, combined with Figure 2 Since the defective ground groove 3 is perpendicular to the extension direction of the signal line 5, the defective ground structure 2 does not affect the transmission of the differential signal. Figure 5 L1 is flat along the horizontal axis; however, it will affect the transmission of common mode noise electromagnetic waves. Figure 5 The L2 has a large fluctuation along the horizontal axis. The common mode noise electromagnetic wave formed can enter the defective ground filter groove 4 connected to the defective ground groove 3 through the defective ground groove 3 and form a reflected electromagnetic wave in the defective ground filter groove 4. Please refer to Figure 6 , Figure 6 This is the spectrum of a common mode noise electromagnetic wave. It can be seen that the decibel value of this common mode noise electromagnetic wave is the largest at 26.5GHz. Please refer to Figure 2 and Figure 7 When the length of the defective ground filter slot 4 is 1 / 4 times the wavelength of the common-mode noise electromagnetic wave, the common-mode insertion loss L2 of the electromagnetic wave at the corresponding frequency is the largest. In order to reduce the common-mode noise as much as possible, the length of the defective ground filter slot 4 (such as Figure 2 The length in the transverse direction can be selected to be 1 / 4 times the wavelength of the noise electromagnetic wave, so that the phase difference between the reflected electromagnetic wave and the common-mode noise electromagnetic wave is 180°, and the reflected electromagnetic wave and the common-mode noise electromagnetic wave cancel each other out, thereby reducing the common-mode noise and, in turn, the electromagnetic interference caused by the common-mode noise. However, if the defective common-mode filter 1 in the related art is to filter the noise electromagnetic wave at a specific frequency, the length of the defective filter slot 4 in the defective common-mode filter 1 needs to be equal to 1 / 4 times the wavelength of the common-mode noise electromagnetic wave at the corresponding frequency, which cannot reduce the size of the defective common-mode filter 1 and the area occupied by the defective common-mode filter 1 on the circuit board.

[0072] Please refer to Figure 8In the embodiment of the present application, the circuit board may have a multi-layer structure, and the circuit board may also include a filter 6. Similarly, the filter 6 provided by the present application may also have a multi-layer structure. For example, the filter 6 may include a routing layer 7 and a filter layer 8, and the routing layer 7 and the filter layer 8 are stacked. Please refer to Figure 9 , Figure 9 The top view of the wiring layer 7 is shown. The wiring layer 7 is provided with a wiring groove 9. The wiring groove 9 is arranged along a fixed direction (such as Figure 9 The signal line 5 on the circuit board is arranged in the wiring groove 9.

[0073] Please refer to Figure 10 and Figure 18 , the filter 6 may also include a filter slot 10 and a connecting slot 11, one end of the filter slot 10 is connected to the connecting slot 11, the extension direction of the connecting slot 11 may be perpendicular to the extension direction of the wiring slot 9, and the connecting slot 11 is connected to the wiring slot 9, so that the first noise electromagnetic wave formed by the signal line 5 (which can be understood as a common-mode noise electromagnetic wave with a specific frequency in the related art) can enter the filter slot 10 through the connecting slot 11 connected to the wiring slot 9, and form a reflected electromagnetic wave in the filter slot 10; the extension direction of the filter slot 10 may be parallel to the extension direction of the wiring slot 9 (that is, the extension direction of the filter slot 10 is parallel to the signal line 5), so that the overall structure of the filter 6 is more compact. Figure 10 As shown, the routing layer 7 may be provided with the above-mentioned filter groove 10 and the connecting groove 11, wherein the filter groove 10 and the connecting groove 11 are arranged on the same layer as the routing groove 9 on the routing layer 7; the filter layer 8 may be provided with the above-mentioned filter groove 10 and the connecting groove 11; in some implementations, the filter layer 8 and the routing layer 7 may be provided with the above-mentioned filter groove 10 and the routing groove 9, wherein the connecting groove 11 located on the routing layer 7 is connected to the connecting groove 11 located on the filter layer 8 in the stacking direction, and the filter groove 10 located on the routing layer 7 is connected to the filter groove 10 located on the filter layer 8 in the stacking direction, which can improve the filtering effect of the first noise electromagnetic wave.

[0074] In order to solve the problems in the related art, the filter 6 provided in the embodiment of the present application may further include a hysteresis structure 12 , which is arranged in the filter slot 10 .

[0075] Continue to refer to Figure 10 In some implementations, the hysteresis structure 12 includes a plurality of hysteresis slots 13, which extend in a direction parallel to the routing layer 7. The hysteresis slot 13 is connected to the filtering slot 10 at one end thereof, and the plurality of hysteresis slots 13 extend along the length direction of the filtering slot 10 (e.g., Figure 10The arrangement of the plurality of hysteresis grooves 13 at equal intervals (in the longitudinal direction) of the filter slot 10, that is, in the longitudinal direction of the filter slot 10, the plurality of hysteresis grooves 13 form a periodically changing structure (i.e., a defective ground structure), and thus the dielectric constant of the filter slot 10 in the longitudinal direction changes periodically, causing the first noise electromagnetic wave to be phase delayed during transmission in the filter slot 10, thereby reducing the propagation speed of the first noise electromagnetic wave in the filter slot 10; according to the formula λ=v / f, where λ is the wavelength of the electromagnetic wave, v is the wave velocity of the electromagnetic wave, and f is the frequency of the electromagnetic wave; then, when the frequency of the first noise electromagnetic wave remains unchanged, the plurality of hysteresis grooves 13 reduce the propagation speed of the first noise electromagnetic wave in the filter slot 10, thereby reducing the wavelength of the first noise electromagnetic wave. As mentioned above, the length of the filter slot 10 needs to be equal to 1 / 4 times the wavelength of the electromagnetic wave of the corresponding frequency. For the first noise electromagnetic wave of the same frequency, the wavelength of the first noise electromagnetic wave is reduced, which can reduce the required length of the filter slot 10, thereby reducing the size of the filter 6.

[0076] Continue to refer to Figure 10 In the above implementation, the extension direction of the hysteresis trough 13 can form an angle (not shown) with the extension direction of the signal line 5. The extension direction of the hysteresis trough 13 can also be perpendicular to the extension direction of the signal line 5. The extension direction of the hysteresis trough 13 being perpendicular to the extension direction of the signal line 5 can make the hysteresis trough 13 and the filter slot 10 more compact, thereby reducing the occupied area of ​​the entire filter 6.

[0077] In the implementation method in which the extension direction of the filter slot 10 is parallel to the signal line 5, the hysteresis slot 13 can be located on the side of the filter slot 10 close to the signal line 5, or on the side of the filter slot 10 away from the signal line 5, or can be located on both the side of the filter slot 10 close to the signal line 5 and the side away from the signal line 5.

[0078] In some implementations where the hysteresis structure 12 includes multiple hysteresis slots 13, the hysteresis slot 13 may further include multiple hysteresis sub-slots 14, with the multiple hysteresis sub-slots 14 being arranged at equal intervals along the length of the filter slot 10. That is, along the length of the filter slot 10, the multiple hysteresis sub-slots 14 may also form a periodically varying structure (i.e., a defective ground structure), which can further reduce the propagation speed of the first noise electromagnetic wave within the filter slot 10, thereby further reducing the wavelength of the first noise electromagnetic wave and reducing the size of the filter 6. In combination with the above implementations, the hysteresis sub-slots 14 may be located on the side of the filter slot 10 close to the signal line 5, on the side of the filter slot 10 away from the signal line 5, or on both the side of the filter slot 10 close to the signal line 5 and the side away from the signal line 5. When the filter 6 in this implementation and the defective ground common mode filter 1 in the related art filter electromagnetic waves of the same frequency, the area required by the filter 6 in this implementation is reduced by 27% compared to the area required by the defective ground common mode filter 1 in the related art.

[0079] Please refer to Figure 11 In some other implementations where the hysteresis structure 12 includes multiple hysteresis slots 13, the hysteresis slot 13 further includes a first slot body 15 and a second slot body 16. The first slot body 15 extends parallel to the routing layer 7 and perpendicular to the signal line 5, and the second slot body 16 extends parallel to the routing layer 7 and the signal line 5. The second slot body 16 is connected to the filter slot 10 through the first slot body 15. Through the above arrangement, the connection between the first slot body 15 and the second slot body 16 can extend the length of the hysteresis slot 13, enhance the effect of the multiple hysteresis slots 13 on reducing the propagation speed of the first noise electromagnetic wave within the filter slot 10, further reduce the wavelength of the first noise electromagnetic wave, thereby reducing the required length of the filter slot 10 and further reducing the size of the filter 6.

[0080] Please refer to Figure 12 and Figure 13 In the above implementation, the hysteresis tank 13 also includes a third tank body 17 and a fourth tank body 18. The third tank body 17 extends in a direction parallel to the routing layer 7 and perpendicular to the signal line 5. The fourth tank body 18 extends in a direction parallel to the routing layer 7 and the signal line 5. The fourth tank body 18 is connected to the filter tank 10 through the third tank body 17. The length of the third tank body 17 in a direction perpendicular to the signal line 5 is less than the length of the first tank body 15 in a direction perpendicular to the signal line 5, so that the third tank body 17 and the fourth tank body 18 are located in the area surrounded by the first tank body 15, the second tank body 16 and the filter tank 10. The third tank body 17 and the fourth tank body 18 increase the number of periodically changing structures connected to the filter tank 10, which can further reduce the propagation speed of the first noise electromagnetic wave in the filter tank 10, thereby further reducing the wavelength of the first noise electromagnetic wave and reducing the size of the filter 6. Wherein, as Figure 12 As shown, the end of the fourth slot body 18 close to the first slot body 15 can be connected to the filter slot 10 through the third slot body 17. Figure 13 As shown, the end of the fourth slot body 18 away from the first slot body 15 can also be connected to the filter slot 10 through the third slot body 17. When the filter 6 in this embodiment and the defective common mode filter 1 in the related art filter the same frequency electromagnetic waves, the area required by the filter 6 in this embodiment is reduced by 30% compared with the area required by the defective common mode filter 1 in the related art. Please refer to Figure 14 The common-mode insertion loss L3 of the filter 6 for electromagnetic waves at the corresponding frequency in this implementation is greater than the common-mode insertion loss L2 in the related art, which improves the filtering effect on the first noise electromagnetic wave.

[0081] Please refer to Figure 15 and Figure 16In other implementations, the filter slot 10 includes a plurality of filter sub-slots 19 spaced apart from each other. The plurality of filter sub-slots 19 are located on the same straight line parallel to the signal line 5, with one end of the filter sub-slot 19 closest to the connecting slot 11 connected to the connecting slot 11. The hysteresis structure 12 includes a plurality of hysteresis connecting slots 20. Except for the filter sub-slot 19 closest to the connecting slot 11, each of the remaining adjacent filter sub-slots 19 is provided with a hysteresis connecting slot 20 and is connected through the hysteresis connecting slot 20. The hysteresis connecting slots 20 are curved or bent relative to the filter sub-slots 19. It is understood that when a first noise electromagnetic wave enters the filter sub-slot 19 closest to the connecting slot 11 from the connecting slot 11, it passes through a hysteresis connecting slot 20 and enters the next filter sub-slot 19, and so on, until it reaches the end of the filter sub-slot 19 farthest from the connecting slot 11, where it returns to form a reflected electromagnetic wave with a phase difference of 180° from the first noise electromagnetic wave. Among them, in order to make the phase difference between the reflected electromagnetic wave and the first noise electromagnetic wave reach 180 degrees, according to the above principle, the transmission path length of the first noise electromagnetic wave in each filter slot 19 and each hysteresis wave connecting slot 20 should be 1 / 4 times the wavelength of the first noise electromagnetic wave. However, since the hysteresis wave connecting slot 20 is bent or curved relative to the filter slot 19, the length of the filter slot 10 including multiple filter sub-slots 19 (that is, the distance between the end of the filter sub-slot 19 closest to the connecting slot 11 and the end of the filter sub-slot 19 farthest from the connecting slot 11 (such as Figure 15 and Figure 16 As shown, the distance from point A to point B is less than 1 / 4 of the wavelength of the first noise electromagnetic wave, reducing the required length of the filter slot 10 and, in turn, the size of the filter 6. In the above implementation, the hysteresis communication slot 20 is curved or bent relative to the filter sub-slot 19, which increases the time it takes for the first noise electromagnetic wave to travel from point A to point B, effectively reducing the propagation speed of the first noise electromagnetic wave within the filter slot 10.

[0082] Continue to refer to Figure 15 and Figure 16 In the implementation mode in which the hysteresis wave structure 12 includes a plurality of hysteresis wave connecting grooves 20, the hysteresis wave connecting grooves 20 include a first section 21 and a second section 22. The first section 21 extends in a direction parallel to the wiring layer 7 and perpendicular to the signal line 5, and the second section 22 extends in a direction parallel to the wiring layer 7 and the signal line 5. There are multiple first sections 21 and second sections 22. Figure 15, multiple second segments 22 are spaced apart in a direction perpendicular to the signal line 5, and the projections of the second segments 22 in the direction perpendicular to the signal line 5 at least partially overlap, wherein the second segment 22 closest to the signal line 5 is connected to a filter sub-slot 19 through a first segment 21, the second segment 22 farthest from the signal line 5 is connected to another filter sub-slot 19 through a first segment 21, and the remaining two adjacent second segments 22 are connected through a first segment 21, for example, the first end of the second segment 22 is connected to the second end of the previous second segment 22 through the first segment 21, and the second end of the second segment 22 is connected to the first end of the next second segment 22 through another first segment 21. Please refer to Figure 16 Among the multiple second segments 22, some are located on one side of the filter sub-slot 19, while another portion is located on the other side of the filter sub-slot 19. The projections of the second segments 22 in a direction perpendicular to the signal line 5 do not overlap. The second segment 22 closest to the filter sub-slot 19 is connected to the filter sub-slot 19 via the first segment 21, and the remaining two adjacent second segments 22 are connected via a single first segment 21. Through the above arrangement, the multiple first segments 21 and the multiple second segments 22 can increase the length of the hysteresis communication slot 20. It can be understood that the longer the length of the hysteresis communication slot 20, the more the length of the filter slot 10 is reduced, and thus the more the size of the filter 6 is reduced.

[0083] The filter 6 provided in the embodiment of the present application, the filter slot 10 and the connecting slot 11 can be arranged on the routing layer 7 or the filter layer 8, or can be arranged on the routing layer 7 and the filter layer 8 at the same time. The extension direction of the filter slot 10 is parallel to the signal line 5. One end of the filter slot 10 is connected to the routing slot 9 through the connecting slot 11. The hysteresis structure 12 is arranged in the filter slot 10. The hysteresis structure 12 can reduce the propagation speed of the first noise electromagnetic wave in the filter slot 10, so as to reduce the required length of the filter slot 10, thereby reducing the size of the filter 6.

[0084] Please refer to Figures 10 to 13 , Figure 15 and Figure 16In the embodiment where the above-mentioned filter slot 10 and connecting slot 11 are provided on the routing layer 7, the filter slot 10 includes a first filter slot 23, and the connecting slot 11 includes a first connecting slot 24. Both the first filter slot 23 and the first connecting slot 24 are provided on the routing layer 7. The extension direction of the first connecting slot 24 is perpendicular to the extension direction of the routing slot 9. The first connecting slot 24 is connected to the routing slot 9. One end of the first filter slot 23 is connected to the routing slot 9 through the first connecting slot 24, so that the first noise electromagnetic wave generated by the signal line 5 can enter the first filter slot 23 through the first connecting slot 24 connected to the routing slot 9 and form a reflected electromagnetic wave in the first filter slot 23 to achieve filtering of the first noise electromagnetic wave; the extension direction of the first filter slot 23 can be parallel to the extension direction of the routing slot 9, so that the overall structure of the filter 6 is more compact. The hysteresis structure 12 includes a first hysteresis structure 25, which is arranged in the first filter slot 23, wherein the first hysteresis structure 25 can include the hysteresis structure 12 including multiple hysteresis slots 13 in the above-mentioned implementation method, or can also include the hysteresis structure 12 including multiple hysteresis connecting slots 20 in the above-mentioned implementation method. The first hysteresis structure 25 can reduce the propagation speed of the first noise electromagnetic wave in the first filter slot 23, so as to reduce the length required for the first filter slot 23, thereby reducing the size of the filter 6.

[0085] In the above embodiment, two first filter slots 23 may be provided, which are located on both sides of the wiring slot 9 respectively. One end of the first connecting slot 24 is connected to one first filter slot 23, and the other end of the first connecting slot 24 is connected to another first filter slot 23. Increasing the number of first filter slots 23 also increases the number of hysteresis structures 12, which can improve the filtering effect of the filter 6 on the first noise electromagnetic wave.

[0086] Please refer to Figure 17 The filter 6 in the above-mentioned implementation and the defective common-mode filter 1 in the related art can both filter electromagnetic waves of the same frequency. That is, the maximum value of the common-mode insertion loss L4 of the filter 6 in this implementation to electromagnetic waves and the maximum value of the common-mode insertion loss L2 in the related art are at the same frequency, but the area required by the filter 6 in this implementation is reduced by 30% compared with the area required by the defective common-mode filter 1 in the related art.

[0087] Please refer to Figures 18 to 23 In the embodiment where the filter layer 8 is provided with the above-mentioned filter groove 10 and the connecting groove 11, the filter layer 8 further includes a first filter layer 26 (such as Figure 8As shown), the routing layer 7 is stacked with the first filter layer 26, the filter slot 10 includes a second filter slot 27, the connecting slot 11 includes a second connecting slot 28, the second filter slot 27 and the second connecting slot 28 are both arranged on the first filter layer 26, the extension direction of the second connecting slot 28 is perpendicular to the extension direction of the routing slot 9, the second connecting slot 28 is connected to the routing slot 9, and one end of the second filter slot 27 is connected to the routing slot 9 through the second connecting slot 28, so that the first noise electromagnetic wave formed by the signal line 5 can enter the second filter slot 27 through the second connecting slot 28 connected to the routing slot 9, and form a reflected electromagnetic wave in the second filter slot 27 to achieve filtering of the first noise electromagnetic wave; the extension direction of the second filter slot 27 can be parallel to the extension direction of the routing slot 9, so as to make the overall structure of the filter 6 more compact. The hysteresis structure 12 includes a second hysteresis structure 29, which is arranged in the second filter slot 27, wherein the second hysteresis structure 29 can include the hysteresis structure 12 including multiple hysteresis slots 13 in the above-mentioned implementation method, or can also include the hysteresis structure 12 including multiple hysteresis connecting slots 20 in the above-mentioned implementation method. The second hysteresis structure 29 can reduce the propagation speed of the first noise electromagnetic wave in the second filter slot 27, so as to reduce the length required for the second filter slot 27, thereby reducing the size of the filter 6.

[0088] In the above embodiment, two second filter slots 27 may be provided, which are located on both sides of the wiring slot 9 respectively. One end of the second connecting slot 28 is connected to one second filter slot 27, and the other end of the second connecting slot 28 is connected to another second filter slot 27. Increasing the number of second filter slots 27 also increases the number of hysteresis structures 12, which can improve the filtering effect of the filter 6 on the first noise electromagnetic wave.

[0089] In an implementation where the filter slots 10 and the connecting slots 11 are provided on both the routing layer 7 and the first filter layer 26, the projection of the first filter slot 23 and the projection of the second filter slot 27 at least partially overlap in a plane parallel to the routing layer 7. This allows the first filter slot 23 and the second filter slot 27 to connect, thereby improving the filtering effect on the first noise electromagnetic wave.

[0090] Continue to refer to Figures 18 to 23 In the above embodiment, the filter layer 8 further includes a second filter layer 30 (such as Figure 8As shown), the wiring layer 7 is stacked and arranged between the first filter layer 26 and the second filter layer 30, the filter slot 10 includes a third filter slot 31, and the connecting slot 11 includes a third connecting slot 32. The third filter slot 31 and the third connecting slot 32 are both arranged on the second filter layer 30, and the extension direction of the third connecting slot 32 is perpendicular to the extension direction of the wiring slot 9. The third connecting slot 32 is connected to the wiring slot 9, and one end of the third filter slot 31 is connected to the wiring slot 9 through the third connecting slot 32, so that the first noise electromagnetic wave formed by the signal line 5 can enter the third filter slot 31 through the third connecting slot 32 connected to the wiring slot 9, and form a reflected electromagnetic wave in the third filter slot 31 to achieve filtering of the first noise electromagnetic wave; the extension direction of the third filter slot 31 can be parallel to the extension direction of the wiring slot 9, so as to make the overall structure of the filter 6 more compact. The hysteresis structure 12 includes a third hysteresis structure 33, which is arranged in the third filter slot 31, wherein the third hysteresis structure 33 may include the hysteresis structure 12 including multiple hysteresis slots 13 in the above-mentioned implementation method, or may include the hysteresis structure 12 including multiple hysteresis connecting slots 20 in the above-mentioned implementation method. The third hysteresis structure 33 can reduce the propagation speed of the first noise electromagnetic wave in the third filter slot 31, so as to reduce the length required for the third filter slot 31, thereby reducing the size of the filter 6.

[0091] In an implementation where the filter slots 10 and the connecting slots 11 are provided on both the routing layer 7 and the second filter layer 30, the projection of the first filter slot 23 and the projection of the third filter slot 31 at least partially overlap in a plane parallel to the routing layer 7. This allows the first filter slot 23 and the third filter slot 31 to connect, thereby improving the filtering effect on the first noise electromagnetic wave.

[0092] In an implementation where the filter slots 10 and the connecting slots 11 are provided on the routing layer 7, the first filter layer 26, and the second filter layer 30, the projections of the first filter slot 23, the second filter slot 27, and the third filter slot 31 at least partially overlap in a plane parallel to the routing layer 7. This allows the first filter slot 23, the second filter slot 27, and the third filter slot 31 to be connected, thereby improving the filtering effect on the first noise electromagnetic wave.

[0093] Continue to refer to Figure 8In the above embodiment, the filter 6 further includes a shielding layer 34, which is stacked with the routing layer 7. The filter layer 8 is located between the shielding layer 34 and the routing layer 7. In an implementation in which the filter layer 8 includes a first filter layer 26 and a second filter layer 30, the shielding layer 34 may include a first shielding layer 35 and a second shielding layer 36. The first shielding layer 35 may be located on a side of the first filter layer 26 facing away from the routing layer 7, and the second shielding layer 36 may be located on a side of the second filter layer 30 facing away from the routing layer 7. The shielding layer 34 is configured to be grounded so that the first noise electromagnetic wave emitted by the signal line 5 located on the routing layer 7 tends to radiate toward the shielding layer 34, thereby facilitating the transmission of the first noise electromagnetic wave within the filter slot 10 provided on the filter layer 8.

[0094] Please refer to Figure 24 In some embodiments, the filter 6 further includes a metal defect layer 37, which is stacked between the routing layer 7 and the shielding layer 34. A cavity 38 is provided in the metal defect layer 37; in a plane parallel to the routing layer 7, the projection of the cavity 38 at least partially overlaps with the projection of the filter slot 10. Through the above arrangement, during the radiation of the first noise electromagnetic wave, the cavity 38 in the metal defect layer 37 increases the routing layer 7 (such as Figure 8 As shown) to the shielding layer 34 (as Figure 8 The distance between the first and second noise electromagnetic waves can be increased, thereby improving the filtering effect of the filter 6 on the first noise electromagnetic wave. Figure 25 The common-mode insertion loss L5 of the filter 6 provided in this embodiment for electromagnetic waves is greater than the common-mode insertion loss L2 in the related art at a specific frequency.

[0095] Continue to refer to Figure 8 In an embodiment in which the filter 6 includes a filter layer 8, the metal defect layer 37 can be located between the filter layer 8 and the shielding layer 34. In an implementation in which the filter layer 8 includes a first filter layer 26 and a second filter layer 30, the metal defect layer 37 can include a first metal defect layer 39 and a second metal defect layer 40, wherein the first metal defect layer 39 can be located between the first filter layer 26 and the first shielding layer 35, and the second metal defect layer 40 can be located between the second filter layer 30 and the second shielding layer 36.

[0096] Please refer to Figure 26In some embodiments, the filter 6 further includes an auxiliary filter slot 41 and an auxiliary hysteresis structure 42. The auxiliary filter slot 41 is connected to the connecting slot 11 and is arranged on the same layer as the filter slot 10. The auxiliary filter slot 41 and the filter slot 10 have different lengths, that is, the auxiliary filter slot 41 can filter the second noise electromagnetic wave, wherein the frequency of the second noise electromagnetic wave is different from that of the first noise electromagnetic wave. The auxiliary filter slot 41 extends in a direction parallel to the signal line 5 to make the overall structure of the filter 6 more compact. The auxiliary hysteresis structure 42 is arranged in the auxiliary filter slot 41, wherein the auxiliary hysteresis structure 42 can include the hysteresis structure 12 including multiple hysteresis slots 13 in the above-mentioned implementation, or can include the hysteresis structure 12 including multiple hysteresis connecting slots 20 in the above-mentioned implementation. The auxiliary hysteresis structure 42 can reduce the propagation speed of the second noise electromagnetic wave in the auxiliary filter slot 41, thereby reducing the length required for the auxiliary filter slot 41 and thereby reducing the size of the filter 6.

[0097] In the above embodiment, the auxiliary filter slot 41 and the filter slot 10 are located on the same straight line parallel to the signal line 5, and the connecting slot 11 is located between the auxiliary filter slot 41 and the filter slot 10. The auxiliary filter slot 41 and the filter slot 10 can share the same connecting slot 11, thereby simplifying the structure of the filter 6 and facilitating a reduction in the size of the filter 6. In combination with the above embodiment, the auxiliary filter slot 41 can be provided on at least one of the routing layer 7 and the filter layer 8.

[0098] The above description is merely a specific embodiment of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A filter, characterized in that: include: A wiring layer, wherein a wiring trough is provided in the wiring layer, and a signal line is provided in the wiring trough; A filter layer, wherein the filter layer and the routing layer are stacked, and a filter slot and a connecting slot are provided on the filter layer and / or the routing layer, wherein the filter slot extends in parallel with the signal line, and one end of the filter slot is connected to the routing slot through the connecting slot; A hysteresis wave structure is provided in the filter slot, and is used to reduce the propagation speed of the first noise electromagnetic wave in the filter slot.

2. The filter according to claim 1, wherein The filter slot includes a first filter slot, the connecting slot includes a first connecting slot, the first filter slot and the first connecting slot are both arranged on the routing layer, and the first filter slot is connected to the routing slot through the first connecting slot; the hysteresis structure is arranged in the first filter slot.

3. The filter according to claim 1 or 2, characterized in that The filter layer also includes a first filter layer, the routing layer is stacked with the first filter layer, the filter slot also includes a second filter slot, the connecting slot also includes a second connecting slot, the second filter slot and the second connecting slot are both arranged on the first filter layer, and the second filter slot is connected to the routing slot through the second connecting slot; the hysteresis structure is arranged in the second filter slot, or in the first filter slot and the second filter slot.

4. The filter according to claim 3, characterized in that The filter layer also includes a second filter layer, the routing layer is stacked between the first filter layer and the second filter layer, the filter slot also includes a third filter slot, the connecting slot also includes a third connecting slot, the third filter slot and the third connecting slot are both arranged on the second filter layer, and the third filter slot is connected to the routing slot through the third connecting slot; the hysteresis structure is arranged in the second filter slot and the third filter slot, or in the first filter slot, the second filter slot and the third filter slot.

5. The filter according to claim 3, wherein In a plane parallel to the routing layer, a projection of the first filter groove and a projection of the second filter groove at least partially overlap.

6. The filter according to claim 4, characterized in that In a plane parallel to the routing layer, a projection of the first filter groove and a projection of the third filter groove at least partially overlap.

7. The filter according to any one of claims 1 to 6, characterized in that: The filter further includes a shielding layer, which is stacked with the routing layer. The filter layer is located between the shielding layer and the routing layer, and the shielding layer is configured to be grounded.

8. The filter according to claim 7, characterized in that The filter also includes a metal defect layer, which is stacked between the routing layer and the shielding layer, and a cavity is provided in the metal defect layer; in a plane parallel to the routing layer, the projection of the cavity at least partially overlaps with the projection of the filter slot.

9. The filter according to any one of claims 1 to 8, characterized in that The hysteresis structure includes a plurality of hysteresis grooves, which are arranged at equal intervals along the length direction of the filter groove. The hysteresis grooves extend in a direction parallel to the routing layer and perpendicular to the signal line. One end of the hysteresis groove close to the filter groove is connected to the filter groove.

10. The filter according to claim 9, characterized in that The hysteresis slot includes a plurality of hysteresis sub-slots, and the plurality of hysteresis sub-slots are arranged on a side of the filter slot close to the signal line and / or on a side of the filter slot far from the signal line.

11. The filter according to claim 9, wherein The hysteresis trough also includes a first trough body and a second trough body, the first trough body extends in a direction parallel to the routing layer and perpendicular to the signal line, the second trough body extends in a direction parallel to the routing layer and the signal line, and the second trough body is connected to the filter trough through the first trough body.

12. The filter according to claim 11, wherein The hysteresis trough also includes a third trough body and a fourth trough body. The third trough body extends in a direction parallel to the routing layer and perpendicular to the signal line. The fourth trough body extends in a direction parallel to the routing layer and the signal line. The fourth trough body is connected to the filtering trough through the third trough body. The third trough body and the fourth trough body are located in an area enclosed by the first trough body, the second trough body and the filtering trough.

13. The filter according to any one of claims 1 to 8, characterized in that: The hysteresis wave structure includes a plurality of hysteresis wave connecting grooves, the filter groove includes a plurality of filter sub-grooves arranged at intervals, the plurality of filter sub-grooves are located on the same straight line parallel to the signal line, a hysteresis wave connecting groove is provided between adjacent filter sub-grooves, and the sub-grooves are connected through the hysteresis wave connecting groove; the hysteresis wave connecting groove is bent or curved relative to the filter sub-grooves.

14. The filter according to claim 13, wherein The hysteresis connecting slot includes a first section and a second section, the first section extends in a direction parallel to the routing layer and perpendicular to the signal line, the second section extends in a direction parallel to the routing layer and the signal line, the second section is connected to the filter sub-slot through one of the first sections, and / or is connected to another of the first sections through one of the first sections.

15. The filter according to any one of claims 1 to 14, characterized in that: The filter also includes an auxiliary filter slot and an auxiliary hysteresis structure. The auxiliary filter slot is arranged on the same layer as the filter slot, the auxiliary filter slot and the filter slot have different lengths, the auxiliary filter slot extends in a direction parallel to the signal line, the auxiliary filter slot is connected to the connecting slot, and the auxiliary hysteresis structure is arranged in the auxiliary filter slot. The auxiliary hysteresis structure is used to reduce the propagation speed of the second noise electromagnetic wave in the auxiliary filter slot, and the frequencies of the first noise electromagnetic wave and the second noise electromagnetic wave are different.

16. The filter according to claim 15, characterized in that The auxiliary filter slot and the filter slot are located on the same straight line parallel to the signal line, and the connecting slot is located between the auxiliary filter slot and the filter slot.

17. A circuit board, characterized in that: The circuit board includes a signal line and the filter according to any one of claims 1 to 16, and the signal line is located in the wiring groove of the filter.

18. An electronic device, characterized in that: The electronic device includes the circuit board according to claim 17.

Images