Suspension coupling structure capacitor suitable for complex electromagnetic environment

Abstract

The application discloses a suspended coupling structure capacitor suitable for a complex electromagnetic environment and belongs to the technical field of capacitors and electromagnetic compatibility. The capacitor comprises a dielectric layer, a top layer conductor electrode arranged on the upper surface of the dielectric layer and a bottom layer conductor electrode arranged on the lower surface of the dielectric layer; an interdigital slot structure is arranged on the top layer conductor electrode, and the interdigital slot structure divides the top layer conductor electrode into a top layer main electrode plate and a top layer suspended electrode plate which are mutually direct current isolated; the top layer main electrode plate and the bottom layer conductor electrode are connected to external circuits as two poles of the capacitor. In this way, by introducing the interdigital slot structure into the top layer conductor electrode, high-frequency electromagnetic interference is spatially coupled to the top layer suspended electrode plate through the interdigital slot structure, a high-frequency filtering path is formed, and thus the high-frequency filtering performance of the capacitor is significantly improved without increasing the direct current leakage current.

Description

Technical Field

[0001] This invention relates to the field of capacitors and electromagnetic compatibility technology, specifically to a suspended coupling structure capacitor suitable for complex electromagnetic environments. Background Technology

[0002] With the rapid development of power electronics technology, the operating frequency of switching power supplies is constantly increasing, and the power density is continuously rising, making electromagnetic compatibility (EMC) issues increasingly prominent. Capacitors, as the most basic passive components in circuits, play a crucial role in filtering, decoupling, and transient suppression. Traditional parallel-plate capacitors use a complete metal plate structure, resulting in a significant high-frequency equivalent series inductance (ESL), which leads to a sharp decline in high-frequency filtering performance. For safety-compliant applications such as Y-capacitors (line-to-ground capacitors), the capacitance value is strictly limited by leakage current—the larger the capacitance value, the larger the power frequency leakage current, and the higher the risk of electric shock to personnel, thus limiting the safety rating of the filter.

[0003] To improve the high-frequency characteristics of capacitors, existing technologies have attempted to introduce distributed inductance and capacitance by etching patterns on the electrodes. For example, by introducing fractal structures or defect ground structures (DGS) on the electrodes, the effective boundary length can be increased within a limited area, thus modulating the frequency response of the transmission line. Fractal capacitors achieve higher capacitance density in the same area by introducing fractal boundaries in planar interdigitated electrodes. However, these technologies still have the following shortcomings:

[0004] First, existing fractal capacitors mostly focus on increasing capacitance density per unit area, enhancing energy storage capacity by maximizing electrode edge length. Their design goal is energy storage in low-frequency or DC applications. For high-frequency filtering applications, increasing the capacitance value often leads to an increase in leakage current, which is subject to safety regulations in Y-capacitor applications.

[0005] Second, existing interdigital capacitor structures typically use the interdigital electrodes directly as the two poles of the capacitor, with the coupling capacitance between the interdigits constituting the device's equivalent capacitance. In this structure, the interdigital electrodes simultaneously perform the dual functions of DC isolation and high-frequency coupling, limiting design freedom and making it difficult to independently optimize DC and high-frequency characteristics.

[0006] Third, existing suspended microstrip lines or suspended substrate technologies are mostly used in filter design, where the entire circuit is suspended in a cavity to reduce losses. However, there are no reports of introducing the concept of suspended patch into capacitor plate structures or optimizing high-frequency filtering functions through plate segmentation and spatial coupling.

[0007] Fourth, existing three-dimensional wound film capacitors generally employ a combination of fractal etching slots and three-dimensional winding structures, introducing distributed inductance and capacitance through the fractal slots. This type of solution relies on the self-similarity and space-filling characteristics of fractal structures, resulting in complex structures, high processing difficulty, and the strong nonlinear effect of the design parameters of the fractal slots (iteration order, line width / spacing, etc.) on performance, leading to long design and debugging cycles.

[0008] Therefore, how to effectively improve the high-frequency filtering performance of capacitors while maintaining their DC characteristics (such as small capacitance and low leakage current), and at the same time simplify the electrode pattern structure to reduce processing difficulty and design cycle, has become a technical problem that urgently needs to be solved in the field of capacitor and electromagnetic compatibility technology. Summary of the Invention

[0009] In view of this, the purpose of the present invention is to provide a suspended coupling structure capacitor suitable for complex electromagnetic environments, so as to improve the high-frequency filtering performance of the capacitor without increasing the DC leakage current, while simplifying the electrode pattern structure to reduce the processing difficulty and design cycle.

[0010] To achieve the above objectives, the present invention adopts the following technical solution: This application provides a suspended coupling structure capacitor suitable for complex electromagnetic environments, comprising: Dielectric layer; The top conductor electrode is disposed on the upper surface of the dielectric layer; The bottom conductor electrode is disposed on the lower surface of the dielectric layer; The top conductor electrode is provided with an interdigitated slot structure, which divides the top conductor electrode into a top main electrode plate and a top suspension electrode plate that are DC isolated from each other. The top main electrode plate and the bottom conductor electrode serve as the two poles of a capacitor, both used to connect to the external circuit.

[0011] Furthermore, in some embodiments of this application, the interdigitated gap structure is a continuous gap, including multiple first gap segments extending along a first direction and second gap segments extending along a second direction; The plurality of first slit segments are arranged at intervals along the second direction, and two adjacent first slit segments are connected by only one second slit segment, and two adjacent second slit segments are connected to different ends of the same first slit segment. The continuous gaps divide the top conductor electrode in the region into multiple alternating first interdigitated electrodes and multiple second interdigitated electrodes. The multiple first interdigitated electrodes are interconnected and belong to the top main electrode plate, and the multiple second interdigitated electrodes are interconnected and belong to the top suspended electrode plate.

[0012] Furthermore, in some embodiments of this application, the first direction is parallel to the width direction of the top conductor electrode.

[0013] Furthermore, in some embodiments of this application, the second direction is parallel to the length direction of the top conductor electrode.

[0014] Furthermore, in some embodiments of this application, the interdigitated gap structure is located at the center of the width direction of the top conductor electrode.

[0015] Furthermore, in some embodiments of this application, the width of the first slit segment and the second slit segment is 0.01mm to 0.5mm, the width of the first interdigitated electrode and the second interdigitated electrode is 0.1mm to 5mm, and the length of the first interdigitated slit is 1mm to 50mm.

[0016] Furthermore, in some embodiments of this application, the top suspended electrode is electrically connected to the bottom conductor electrode through a conductive via penetrating the dielectric layer.

[0017] Furthermore, in some embodiments of this application, the conductive via is disposed in the interdigitated electrode region of the top suspended electrode plate, and the diameter of the conductive via is 0.05mm to 1mm.

[0018] Furthermore, in some embodiments of this application, the bottom conductor electrode is also provided with an interdigitated slot structure, which divides the bottom conductor electrode into a bottom main electrode plate and a bottom suspension electrode plate that are DC isolated from each other. The bottom main plate and the top main plate serve as the two poles of a capacitor, both used to connect to the external circuit.

[0019] Furthermore, in some embodiments of this application, the material of the dielectric layer is polyimide, liquid crystal polymer, polyethylene terephthalate, or polyethylene naphthalate, and the thickness of the dielectric layer is 10 μm to 500 μm.

[0020] The suspended coupling structure capacitor provided in this application, suitable for complex electromagnetic environments, has the following advantages: 1. DC and high-frequency characteristics can be optimized independently. This application divides the top conductor electrode into a top main plate and a top suspended plate, and utilizes an interdigitated gap structure to achieve spatial coupling of high-frequency signals. DC isolation is ensured by the interdigitated gaps, while high-frequency coupling is achieved by interdigitated capacitors. The capacitance value of the main capacitor determines the DC leakage current and low-frequency filtering characteristics, while the size of the interdigitates determines the high-frequency coupling strength—the two can be designed independently without interference. This characteristic is particularly important for safety applications such as Y capacitors: excellent high-frequency filtering performance can be obtained by optimizing the interdigitates while maintaining a small capacitance value (low leakage current, high safety level).

[0021] 2. Simple structure, easy to process and mass-produce. Compared with fractal etching schemes, this application adopts a regular interdigitated gap structure with regular pattern and single parameters (gap width, interdigitated width, interdigitated length, interdigitated quantity). It can be realized using standard flexible printed circuit board (FPCB) technology, without the need for complex photomask design and multi-stage iterative pattern processing, resulting in low cost, high yield and good consistency.

[0022] 3. Multiple resonant frequencies and adjustable filtering bandwidth. The interdigitated slot structure is essentially a distributed parameter network, and its equivalent circuit contains multiple resonant units. By adjusting the geometric parameters of the interdigitated slot structure (slot width, interdigit width, interdigit length, and interdigit magnitude), multiple transmission zeros and poles can be generated, achieving high insertion loss over a wide bandwidth. This characteristic makes the suspended coupling structure capacitor provided in this application, suitable for complex electromagnetic environments, particularly suitable for suppressing wideband electromagnetic interference in switching power supplies, DC-DC converters, etc.

[0023] 4. It can be flexibly expanded into a multi-level coupling structure. The basic unit of this application (main electrode plate - interdigitated gap - suspension electrode plate) can be easily expanded into a multi-level structure: by introducing multiple interdigitated gaps between the main electrode plate and the suspension electrode plate, or by symmetrically setting the same interdigitated gap structure on the bottom conductor electrode, a multi-level high-frequency coupling network can be formed, further improving the filtering performance and out-of-band suppression capability.

[0024] 5. Applicable to three-dimensional winding structures. The suspended coupling structure capacitor of this application, suitable for complex electromagnetic environments, can be realized based on a flexible dielectric thin film, which is wound into a three-dimensional winding structure. This achieves higher capacitance density and more complex electric field coupling paths within a limited volume, further expanding high-frequency filtering performance. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is an exploded view of the suspended coupling structure capacitor suitable for complex electromagnetic environments provided in the embodiments of the present invention; Figure 2 This is an exploded view of a suspended coupling structure capacitor suitable for complex electromagnetic environments, provided by another embodiment of the present invention. Figure 3 This is an exploded view of a suspended coupling structure capacitor suitable for complex electromagnetic environments, provided in another embodiment of the present invention. Figure 4 This is a test curve of the S21 transfer coefficient of the suspended coupling structure capacitor suitable for complex electromagnetic environments provided in various embodiments of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0028] Figure 1 This is an exploded view of the suspended coupling structure capacitor suitable for complex electromagnetic environments provided in an embodiment of the present invention. Please refer to [link / reference]. Figure 1 ( Figure 1 In the figure, the two vertical lines that cut off the capacitor from top to bottom indicate that the capacitor shown is not the full length of the capacitor (the same applies below). The suspended coupling structure capacitor suitable for complex electromagnetic environments provided in this embodiment includes: a dielectric layer 1, a top conductor electrode 2, and a bottom conductor electrode 3.

[0029] Specifically, the top conductor electrode 2 is disposed on the upper surface of the dielectric layer 1; the bottom conductor electrode 3 is disposed on the lower surface of the dielectric layer 1.

[0030] Among them, the top conductor electrode 1 is provided with an interdigitated slot structure 4, which divides the top conductor electrode 2 into a top main electrode plate 21 and a top suspended electrode plate 22 that are DC isolated from each other; the top main electrode plate 21 and the bottom conductor electrode 3 serve as the two poles of a capacitor and are used to connect to the external circuit.

[0031] It should be noted that the suspended coupling structure capacitor provided in this application embodiment, suitable for complex electromagnetic environments, has a top main plate 21 and a bottom conductor electrode 3 forming the main capacitor, which performs DC isolation and low-frequency filtering functions. The top main plate 21 and the top suspended plate 22 are coupled via an interdigital slot structure 4. For DC and low-frequency signals, the interdigital slot structure 4 has extremely high impedance, maintaining DC isolation between the top main plate 21 and the top suspended plate 22, thus not increasing the DC leakage current of the capacitor. For high-frequency electromagnetic interference, the interdigital slot structure 4 provides a low-impedance coupling path, allowing high-frequency signals to couple spatially from the top main plate 21 to the top suspended plate 22, forming an additional high-frequency filtering channel. Since the top suspended plate 22 is in a suspended state (i.e., not directly connected to an external circuit), its potential fluctuates with the high-frequency interference signal, effectively creating a high-frequency bypass capacitor in parallel with the main capacitor, thereby significantly improving the high-frequency filtering effect without changing the DC characteristics.

[0032] Furthermore, in some embodiments of this application, such as Figure 1 As shown, the interdigitated slot structure 4 is a continuous slot, including multiple first slot segments 41 extending along a first direction and second slot segments 42 extending along a second direction; wherein, the multiple first slot segments 41 are arranged at intervals along the second direction, and adjacent two first slot segments 41 are connected only by one second slot segment 42, and adjacent two second slot segments 42 are connected to different ends of the same first slot segment 41; the continuous slot divides the top conductor electrode 21 in the region into multiple alternating first interdigitated electrodes 211 and multiple second interdigitated electrodes 221, the multiple first interdigitated electrodes 211 are interconnected and belong to the top main electrode plate 21, and the multiple second interdigitated electrodes 221 are interconnected and belong to the top suspended electrode plate 11.

[0033] In the suspended coupling structure capacitor suitable for complex electromagnetic environments provided in the above embodiments, the widths of the first slot segment 41 and the second slot segment 42 can be 0.01mm to 0.5mm, the widths of the first interdigitated electrode 211 and the second interdigitated electrode 222 can be 0.1mm to 5mm, and the length of the first interdigitated slot 41 can be 1mm to 50mm. Of course, in practical applications, the dimensions of the interdigitated fingers, such as the slot width, interdigitated finger width, interdigitated finger length, and interdigitated index, can be independently and flexibly adjusted according to actual needs, thereby controlling the strength and frequency characteristics of high-frequency coupling. In particular, by adjusting the slot width and the interdigitated index, the high-frequency coupling capacitance value can be precisely controlled, achieving regulation of the filter cutoff frequency and out-of-band rejection characteristics.

[0034] Furthermore, in some embodiments of this application, the first direction is parallel to the width direction of the top conductor electrode. In this case, the second direction can be parallel to the length direction of the top conductor electrode. Of course, in other embodiments of this application, the first and second directions can also be other directions, as long as it can achieve the division of the top conductor electrode 2 into a top main electrode plate 21 and a top suspension electrode plate 22 that are DC isolated from each other.

[0035] Furthermore, in some embodiments of this application, the interdigitated gap structure 4 is located at the center of the width direction of the top conductor electrode 2. In this case, the top main electrode plate 21 and the top suspended electrode plate 22 have the same area and structure, forming a symmetrical design. Of course, in other embodiments of this application, the interdigitated gap structure 4 can also be arranged off-center, such as making the area of ​​the top suspended electrode plate 22 smaller than that of the top main electrode plate 21, thereby adjusting the strength of high-frequency coupling according to actual needs.

[0036] Figure 2 This is an exploded view of a suspended coupling structure capacitor suitable for complex electromagnetic environments, provided by another embodiment of the present invention. Figure 2As shown, in some embodiments of this application, the top suspended electrode 22 can be electrically connected to the bottom conductor electrode 3 through a conductive via 5 penetrating the dielectric layer 1.

[0037] Specifically, the top suspended electrode 22 is electrically connected to the bottom conductor electrode 3 through a conductive via 5 penetrating the dielectric layer 1. At this time, the top suspended electrode 22 forms a high-frequency coupling with the top main electrode 21 through the interdigitated slot structure 4, and simultaneously forms a DC connection with the bottom conductor electrode 3 through the conductive via 5.

[0038] Understandably, in this embodiment, the top suspended electrode 22 effectively becomes an extension of the bottom conductor electrode 3 on the top layer, while the interdigitated slot structure 4 forms a high-frequency coupling path between the top main electrode and the bottom conductor electrode. This increases design flexibility, and in practical applications, the high-frequency coupling characteristics can be controlled by adjusting the via position and density.

[0039] In practical applications, the conductive via 5 is preferably located in the interdigitated electrode area of ​​the top suspended electrode plate 22, and the via diameter can be 0.05mm to 1mm.

[0040] Figure 3 This is an exploded view of a suspended coupling structure capacitor suitable for complex electromagnetic environments, provided in another embodiment of the present invention. Figure 3 As shown, in some embodiments of this application, the bottom conductor electrode 3 may also be provided with an interdigitated gap structure, which divides the bottom conductor electrode 3 into a bottom main electrode plate and a bottom suspended electrode plate that are DC isolated from each other; in this embodiment, the bottom main electrode plate and the top main electrode plate serve as the two poles of a capacitor and are both used to connect to the external circuit.

[0041] It is understood that the suspended coupling structure capacitor provided in this embodiment, suitable for complex electromagnetic environments, is a bi-directional symmetrical structure. Both the top and bottom conductor electrodes incorporate suspended plates, further increasing high-frequency coupling paths and improving high-frequency filtering performance. In this embodiment, both the top and bottom suspended plates are in a suspended state, and their potentials can float independently with high-frequency interference signals to form a multi-path high-frequency coupling network.

[0042] In practical applications, the dielectric layer of the suspended coupling structure capacitor suitable for complex electromagnetic environments provided in the above embodiments can be made of polyimide, liquid crystal polymer, polyethylene terephthalate, or polyethylene naphthalate, with a thickness of 10 μm to 500 μm. The top and bottom conductor electrodes can be made of copper, aluminum, silver, or their alloys, with a thickness of 5 μm to 70 μm. These electrodes can be formed by magnetron sputtering, electroplating, or chemical plating, followed by photolithography or laser direct writing to etch the interdigitated slot structure pattern. The capacitor mentioned in the above embodiments can be wound to form a three-dimensional winding structure with more than two turns. It is understood that the winding structure can achieve a longer electrode length and a larger effective area within a limited volume, thereby further improving the capacitance density of the suspended coupling structure capacitor suitable for complex electromagnetic environments in this application.

[0043] The following three examples of actual capacitors and their actual production demonstrate the design of the suspended coupling structure capacitor suitable for complex electromagnetic environments proposed in this application: Example 1: The suspended coupling structure capacitor provided in this embodiment, suitable for complex electromagnetic environments, is a capacitor with an interdigitated slot structure only on the top conductor electrode; that is, a capacitor based on a suspended patch interdigitated coupling structure. The specific structure is as follows: Figure 1 As shown: (1) The structure consists of a top conductor electrode 2, a dielectric layer 1, and a bottom conductor electrode 3. The top conductor electrode 2 is divided into two DC-isolated parts by an interdigitated gap structure 4, namely the top main electrode 21 and the top suspended electrode 22. The top main electrode 21 and the bottom conductor electrode 3 are connected to the external circuit as the two electrodes of the capacitor, forming the external connection of the capacitor. Although the top main electrode 21 and the top suspended electrode 22 form DC isolation under the action of the interdigitated gap structure 4, high-frequency electromagnetic interference can be spatially coupled to the top suspended electrode 22 through the interdigitated gap structure 4, resulting in a better filtering effect for high-frequency electromagnetic interference.

[0044] (2) such as Figure 1 The exploded view of the structure shown can actually be fabricated using a flexible printed circuit board. The dielectric layer 1 is a PI film with a thickness d2 = 127 μm. The flexible board is 590 mm long and 40 mm wide. The relative permittivity of the PI film on the flexible board is 3.5, and the loss tangent is 0.008 S / m.

[0045] (3) From top to bottom: top conductor electrode 2 (copper, thickness d1=18μm), dielectric layer 1 (PI film, thickness d2=127μm), bottom conductor electrode 3 (copper, thickness d1=18μm).

[0046] (4) The top conductor electrode is etched with an interdigitated structure (i.e., an interdigitated gap structure), the gap width is 0.05 mm, and the interdigitated electrode (i.e., as shown in the figure) Figure 1 The two adjacent, semi-enclosed white electrode portions (excluding other white electrode portions connected to these portions) shown in the diagram have a width of 1 mm and a length of 20 mm. A periodic interdigitated slot structure divides the top conductor electrode 2 into two non-communicating parts. The interdigitated slot structure 4 can be offset or located at the center of the width direction of the top conductor electrode 2. In this embodiment, the interdigitated slot structure 4 is located at the center of the width direction, thus forming a top main electrode plate 21 and a top suspended electrode plate 22 with identical structures.

[0047] Example 2: The suspended coupling structure capacitor provided in this embodiment, suitable for complex electromagnetic environments, is a capacitor with an interdigitated slot structure only on the top conductor electrode and conductive vias. In other words, it is a capacitor based on a two-electrode interdigitated coupling structure. The specific structure is as follows: Figure 2 As shown: (1) The structure consists of a top conductor electrode 2, a dielectric layer 1, and a bottom conductor electrode 3. The top conductor electrode 2 is divided into two DC-isolated parts, the top main electrode 21 and the top suspension electrode 22, by an interdigitated slot structure 4. The top main electrode 21 and the bottom conductor electrode 3 are connected to the external circuit as the two electrodes of the capacitor, forming the external connection of the capacitor. The top suspension electrode 22 is connected to the bottom conductor electrode 3 through periodic vias 5. Although the top main electrode 21 and the top suspension electrode 22 form DC isolation under the action of the interdigitated slot structure 4, high-frequency electromagnetic interference can be spatially coupled to the top suspension electrode 21 through the interdigitated slot structure 4, resulting in a better filtering effect for high-frequency electromagnetic interference.

[0048] (2) such as Figure 2 The exploded view of the structure shown can actually be fabricated using a flexible printed circuit board. The dielectric layer 1 is a PI film with a thickness d2 = 127 μm. The flexible board is 590 mm long and 40 mm wide. The relative permittivity of the PI film on the flexible board is 3.5, and the loss tangent is 0.008 S / m.

[0049] (3) From top to bottom: top conductor electrode 2 (copper, thickness d1=18μm), dielectric layer 1 (PI film, thickness d2=127μm), bottom conductor electrode 3 (copper, thickness d1=18μm).

[0050] (4) An interdigitated structure is etched on the top conductor electrode layer. The gap width is 0.05 mm, the width of the interdigitated electrode is 1 mm, and the length is 20 mm. The periodic interdigitated gap structure divides the top conductor electrode 2 into two non-connected parts. The interdigitated gap structure 4 can be offset or located at the center of the length direction of the top conductor electrode layer 2. In this embodiment, the interdigitated gap structure 4 is located at the center of the width direction, so that the top main electrode plate 21 and the top suspended electrode plate 22 formed are exactly the same structure.

[0051] (5) The top suspended electrode 22 is connected to the bottom conductor electrode 3 through periodic conductive vias 5. The diameter of the via is 0.2 mm, and the height is the sum of the thicknesses of the top conductor electrode 2 (copper, thickness d1=18 μm), the dielectric layer 1 (PI film, thickness d2=127 μm), and the bottom conductor electrode 3 (copper, thickness d1=18 μm), which is 0.163 mm. The center of the conductive via 5 is located at the center of each interdigitated electrode of the top suspended electrode 22 and offset by a segment of interdigitated gap by 0.5 mm.

[0052] Example 3: The suspended coupling structure capacitor provided in this embodiment, suitable for complex electromagnetic environments, has interdigitated slot structures on both the top and bottom conductor electrodes; that is, it is a capacitor based on a bipolar suspended patch interdigitated coupling structure. The specific structure is as follows: Figure 3 As shown: (1) The structure consists of a top conductor electrode 2, a dielectric layer 1, and a bottom conductor electrode 3. The top conductor electrode 2 is divided into two DC-isolated parts by an interdigitated gap structure 4, namely the top main electrode 21 and the top suspension electrode 22. The bottom conductor electrode 3 is also divided into two DC-isolated parts by the interdigitated gap structure 4, namely the bottom main electrode 31 and the bottom suspension electrode 32. The top main electrode 21 and the bottom main electrode 31 are connected to the external circuit as the two stages of the capacitor, forming the external connection of the capacitor. Although the bottom main electrode 31 and the bottom suspension electrode 32 form DC isolation under the action of the interdigitated gap structure 4 on the bottom conductor electrode, high-frequency electromagnetic interference can be spatially coupled to the bottom suspension electrode 32 through the interdigitated gap structure 4, resulting in a better filtering effect for high-frequency electromagnetic interference.

[0053] (2) such as Figure 1 The exploded view of the structure shown is fabricated using a flexible printed circuit board. The dielectric layer 1 is a PI film (thickness d2 = 127 μm). The flexible board is 590 mm long and 40 mm wide. The relative permittivity of the PI film on the flexible board is 3.5, and the loss tangent is 0.008 S / m.

[0054] (3) From top to bottom: top conductor electrode 2 (copper, thickness d1=18μm), dielectric layer 1 (PI film, thickness d2=127μm), bottom conductor electrode 3 (copper, thickness d1=18μm).

[0055] (4) The top conductor electrode 2 is etched with an interdigitated structure. The gap width is 0.05 mm, the width of the interdigitated electrode is 1 mm, and the length is 20 mm. The periodic interdigitated gap structure divides the top conductor electrode 2 into two non-connected parts. In this embodiment, the interdigitated gap structure 4 is offset, so that the edge of the top suspension plate 22 formed is 2 mm away from the root of the interdigitated gap structure instead of 10 mm.

[0056] (5) Similarly, the bottom conductor electrode 3 is also etched with an interdigitated structure, with a gap width of 0.05 mm, a width of 1 mm, and a length of 20 mm. The periodic interdigitated gap structure divides the bottom conductor electrode 3 into two non-connected parts. Furthermore, the interdigitated gap structure is offset, so that the edge of the bottom suspension plate 32 formed is 2 mm away from the root of the interdigitated gap structure, rather than 10 mm.

[0057] like Figure 4 As shown, the capacitors formed in typical cases 1, 2, and 3 were used to establish an RF transmission / reflection test environment using a network analyzer, and S21 curves were obtained under different structures.

[0058] Preliminary results show that the frequency response characteristics of the device significantly change after introducing the etched interdigitated slot structure, manifested in the shift, broadening, and multiple resonant frequencies. Based on the actual test characteristics, it can be applied to the Y-capacitor (line-to-ground capacitor) of the filter. Compared with traditional parallel-plate capacitors, it has better low-frequency suppression characteristics. Furthermore, the low-frequency capacitance is very small, resulting in lower leakage current for AC filters, reducing the risk of electric shock and improving the safety rating of the filter.

[0059] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0060] It should be noted that in the description of this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means at least two.

[0061] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0062] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0063] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0064] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0065] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0066] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0067] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A suspended coupling structure capacitor suitable for complex electromagnetic environments, characterized in that, include: Dielectric layer; The top conductor electrode is disposed on the upper surface of the dielectric layer; The bottom conductor electrode is disposed on the lower surface of the dielectric layer; The top conductor electrode is provided with an interdigitated slot structure, which divides the top conductor electrode into a top main electrode plate and a top suspension electrode plate that are DC isolated from each other. The top main electrode plate and the bottom conductor electrode serve as the two poles of a capacitor, both used to connect to the external circuit.

2. The suspended coupling structure capacitor suitable for complex electromagnetic environments according to claim 1, characterized in that, The interdigitated gap structure is a continuous gap, including multiple first gap segments extending along a first direction and second gap segments extending along a second direction; The plurality of first slit segments are arranged at intervals along the second direction, and two adjacent first slit segments are connected by only one second slit segment, and two adjacent second slit segments are connected to different ends of the same first slit segment. The continuous gaps divide the top conductor electrode in the region into multiple alternating first interdigitated electrodes and multiple second interdigitated electrodes. The multiple first interdigitated electrodes are interconnected and belong to the top main electrode plate, and the multiple second interdigitated electrodes are interconnected and belong to the top suspended electrode plate.

3. The suspended coupling structure capacitor suitable for complex electromagnetic environments according to claim 2, characterized in that, The first direction is parallel to the width direction of the top conductor electrode.

4. The suspended coupling structure capacitor suitable for complex electromagnetic environments according to claim 3, characterized in that, The second direction is parallel to the length direction of the top conductor electrode.

5. The suspended coupling structure capacitor suitable for complex electromagnetic environments according to claim 4, characterized in that, The interdigitated gap structure is located at the center of the width direction of the top conductor electrode.

6. The suspended coupling structure capacitor suitable for complex electromagnetic environments according to claim 2, characterized in that, The width of the first slit segment and the second slit segment is 0.01mm to 0.5mm, the width of the first interdigitated electrode and the second interdigitated electrode is 0.1mm to 5mm, and the length of the first interdigitated slit is 1mm to 50mm.

7. The suspended coupling structure capacitor suitable for complex electromagnetic environments according to claim 1, characterized in that, The top suspended electrode plate is electrically connected to the bottom conductor electrode through a conductive via penetrating the dielectric layer.

8. The suspended coupling structure capacitor suitable for complex electromagnetic environments according to claim 7, characterized in that, The conductive via is disposed in the interdigitated electrode area of ​​the top suspended electrode plate, and the diameter of the conductive via is 0.05mm to 1mm.

9. The suspended coupling structure capacitor suitable for complex electromagnetic environments according to claim 1, characterized in that, The bottom conductor electrode is also provided with an interdigitated slot structure, which divides the bottom conductor electrode into a bottom main electrode plate and a bottom suspension electrode plate that are DC isolated from each other. The bottom main plate and the top main plate serve as the two poles of a capacitor, both used to connect to the external circuit.

10. The suspended coupling structure capacitor suitable for complex electromagnetic environments according to claim 1, characterized in that, The dielectric layer is made of polyimide, liquid crystal polymer, polyethylene terephthalate, or polyethylene naphthalate, and the thickness of the dielectric layer is 10 μm to 500 μm.

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