A high shielding degree rigid-flex board fast interconnection structure based on EBG

Abstract

The application belongs to the technical field of signal transmission, and particularly relates to a high-shielding rigid-flex board fast interconnection structure based on EBG, which is composed of two same port structures, wherein one port comprises a flexible board strip line 1 and a rigid board microstrip line 2. The other end structure of the interconnection structure is the same as the one. The rigid board microstrip line of one port and the inverted rigid board microstrip line of the other port are attached, and are fixed by screws through mounting holes, so that the interconnection of microwave signals is finally realized, wherein the surface patterns of the rigid board microstrip line and the inverted rigid board microstrip line coincide, the application adopts the EBG structure, has high tolerance to air gaps and alignment errors of the interconnection end face, reduces signal leakage, and improves shielding effectiveness.

Description

Technical Field

[0001] This application belongs to the field of signal transmission technology, and specifically relates to a high-shield rigid-flex board rapid interconnection structure based on EBG. Background Technology

[0002] Currently, complex antenna RF systems often involve intricate cabling within confined spaces. A large number of cables can lead to electromagnetic compatibility (EMC) issues, and the high profile of the connectors used in cable joints does not meet the current demand for thinner and lighter RF systems. To achieve extremely thin RF system circuits, it is necessary to change the traditional RF signal transmission methods such as using cable connectors. A rigid microwave board is used in the planar circuit section, while a flexible board is used where bending is required. The interconnection of RF signals between the rigid and flexible boards is achieved through a rigid-flex board interconnect structure.

[0003] Rigid-flex interconnect structures enable the interconnection of radio frequency signals between rigid and flexible microwave boards. This can be achieved by laminating rigid and flexible boards together and punching metallized vias during PCB fabrication. However, due to limitations in PCB fabrication technology, some rigid-flex boards cannot be laminated. Reference [1] proposes a method for soldering signal lines between flexible and rigid boards. However, in high-frequency, high-density flexible interconnects, the extremely thin substrate results in a small inter-line spacing between coplanar waveguide transmission lines, leading to low soldering reliability. Furthermore, if microwave signal interconnects are soldered using PCBs, they cannot be disassembled, thus losing maintainability. On the other hand, if general microwave transmission lines are interconnected using PCBs, they cannot achieve the high shielding performance of connector interconnects. An additional electromagnetic shielding cover needs to be added to the PCB interconnect structure, which also increases the volume occupied by the interconnect structure, making it difficult to achieve ultra-thin interconnection of microwave signals.

[0004] References:

[0005] [1] Li Yugang, Ge Xinling, Jiang Wanshun. A flexible interconnect based on coplanar waveguide transmission lines [C]. Proceedings of the 2017 National Microwave and Millimeter Wave Conference (Volume 2). 2017. Summary of the Invention

[0006] To address the aforementioned issues, this application provides a high-shield rigid-flex plate rapid interconnection structure based on EBG, used to connect striplines at the ports of two structures.

[0007] The interconnection structures at the two ports are identical, and the interconnection structure at one port includes:

[0008] The strip line is arranged between the middle dielectric plate and the lower dielectric plate, and the lower floor is arranged on the lower layer below the lower dielectric plate;

[0009] An upper floor plate arranged on top of the intermediate dielectric plate, a second upper dielectric plate arranged on top of the upper floor plate, a first upper dielectric plate arranged on top of the second upper dielectric plate; and microstrip lines attached to the upper surface of the first upper dielectric plate.

[0010] The microstrip line is connected to the stripline through signal holes passing through the first upper dielectric substrate, the second upper dielectric substrate, and the middle dielectric substrate; both the microstrip line and the stripline are surrounded by shielding structures.

[0011] During connection, the first upper dielectric substrates of the interconnect structure at the two ports overlap to make the microstrip lines of the two interconnect structures interconnect and conduct, and the interconnect structures are fixedly connected by fasteners.

[0012] Preferably, the shielding structure of the microstrip line includes: a plurality of metal holes with metal coatings on the walls of the second upper dielectric substrate, the plurality of metal holes being distributed circumferentially around the microstrip line.

[0013] Preferably, there are multiple metal sheets between the first upper dielectric plate and the second upper dielectric plate, each metal sheet overlapping with one of the metal holes.

[0014] Preferably, multiple metal holes are symmetrically distributed along the centerline of the microstrip line, so that when the microstrip lines of the two interconnect structures are overlapped, the metal sheets of the two interconnect structures correspond one-to-one.

[0015] Preferably, the signal hole is a through hole with a metal plating on its wall, and the upper plate has a through hole with a diameter larger than that which is not connected to the signal hole.

[0016] Preferably, the shielding structure of the stripline includes a grounding hole passing through an upper ground plane, a middle dielectric plate, a lower dielectric plate, and a lower ground plane, wherein the inner wall of the grounding hole has a metal plating layer.

[0017] Preferably, the first upper dielectric plate and the second upper dielectric plate are rigid dielectric plates, while the middle dielectric plate and the lower dielectric plate are flexible dielectric plates.

[0018] Preferably, the thickness of the first upper dielectric plate, the second upper dielectric plate, the middle dielectric plate, and the lower dielectric plate is 0.254 mm.

[0019] Preferably, the width of the strip is 0.35 mm.

[0020] Preferably, the signal aperture diameter is 0.24 mm.

[0021] The advantages of this application include:

[0022] 1. The EBG structure allows for greater tolerance to installation errors, reducing signal leakage and improving shielding effectiveness.

[0023] 2. It adopts screw fixing and signal line contact transmission method, eliminating the need for connectors, soldering, reducing costs, and enabling rapid interconnection.

[0024] 3. This invention can be widely applied to high-density three-dimensional rapid interconnection of microwave signals, such as conformal antennas, smart skins, wearable devices, etc. Attached Figure Description

[0025] Figure 1 This is an interconnection structure diagram of a preferred embodiment of this application;

[0026] Figure 2 This is a preferred embodiment of the interconnection structure stack-up diagram of this application;

[0027] Figure 3 This is a schematic diagram of a preferred embodiment of the two-port stacked structure of this application;

[0028] Figure 4 This is a partial diagram of the interconnection EBG according to a preferred embodiment of this application. Detailed Implementation

[0029] To make the technical solution and advantages of this application clearer, the technical solution of this application will be described in a clearer and more complete manner below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of this application, and are only used to explain this application, not to limit this application. It should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings. Other related parts can be referred to the general design. In the absence of conflict, the embodiments and technical features in the embodiments of this application can be combined with each other to obtain new embodiments.

[0030] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., used in this application description to indicate relative direction or positional relationship are used only to indicate relative orientation or positional relationship, and do not imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. When the absolute position of the described object changes, its relative positional relationship may also change accordingly, and therefore should not be construed as a limitation on this application. The terms "first," "second," "third," and similar terms used in this application description are used only for descriptive purposes to distinguish different components, and should not be construed as indicating or implying relative importance. The terms "a," "one," or "the," etc., used in this application description should not be construed as an absolute limitation on quantity, but should be construed as indicating the existence of at least one. The terms "including," "comprising," etc., used in this application description mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0031] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, terms such as “installation,” “connection,” and “linkage” used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can 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 connection within two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0032] This application provides a high-shield rigid-flex board rapid interconnect structure based on EBG for connecting striplines 70 at two structural ports; it consists of two identical port structures. One port is as follows: Figure 1 As shown, it includes a flexible plate microstrip line 1 and a rigid plate microstrip line 2. The other end of the interconnect structure is the same. The rigid plate microstrip line at one end and the inverted rigid plate microstrip line at the other end are bonded together and fixed with screws through mounting holes, ultimately achieving the interconnection of microwave signals, as shown. Figure 3 As shown. The surface patterns of the rigid plate microstrip line and the inverted rigid plate microstrip line coincide. The interconnection ports are stacked as follows. Figure 2 As shown, the components are microstrip line 10, upper dielectric substrate 20, EBG structure 30, upper dielectric substrate 40, upper ground plane 50, middle dielectric substrate 60, stripline 70, lower dielectric substrate 80, and lower ground plane 90, which specifically include:

[0033] The interconnection structures at the two ports are identical, and the interconnection structure at one port includes:

[0034] A strip line 70 is arranged between the intermediate dielectric plate 60 and the lower dielectric plate 80, and a lower floor 90 is arranged on the lower layer below the lower dielectric plate 80.

[0035] An upper floor 50 is arranged on the upper layer of the intermediate dielectric plate 60; a second upper dielectric plate 40 is arranged on the upper layer of the upper floor 50; a first upper dielectric plate 20 is arranged on the upper layer of the second upper dielectric plate 40; and a microstrip line 10 is attached to the upper surface of the first upper dielectric plate 20.

[0036] The microstrip line 10 is connected to the stripline 70 through a signal hole 22 passing through the first upper dielectric substrate 20, the second upper dielectric substrate 40, and the middle dielectric substrate 60; both the microstrip line 10 and the stripline 70 are surrounded by shielding structures.

[0037] During connection, the first upper dielectric substrate 20 of the interconnect structure at the two ports overlaps to make the microstrip lines 10 of the two interconnect structures interconnected and connected, and the interconnect structures are fixedly connected by fasteners.

[0038] Its working principle: The lower ground plane 90, lower dielectric plate 80, stripline 70, middle dielectric plate 60, and upper ground plane 50 constitute a flexible stripline, which achieves electromagnetic shielding through grounding holes 51, 61, 81, and 91; the upper dielectric plate 20, upper dielectric plate 40, microstrip line 10, and upper ground plane 50 constitute a rigid microstrip line; the flexible stripline passes through signal holes 62, 42, and 22 and then through signal ground hole 52 before being converted into a rigid microstrip line; EBG structure 30 and EBG structure 41 constitute an EBG structure at one end.

[0039] The other port structure is inverted and covers the first port structure. It is fixed with screws through the mounting holes so that the surface pattern of the rigid plate microstrip line and the inverted rigid plate microstrip line coincide.

[0040] One end of the EBG structure and the other end of the EBG structure covering it together constitute the EBG structure of the entire interconnection structure, realizing the electromagnetic shielding of the entire interconnection structure.

[0041] In some alternative embodiments, the shielding structure of the microstrip line 10 includes a plurality of metal holes 41 with metal coatings on the walls of the second upper dielectric substrate 40, the plurality of metal holes 41 being distributed circumferentially around the microstrip line 10.

[0042] In some alternative embodiments, a plurality of metal sheets 30 are provided between the first upper dielectric plate 20 and the second upper dielectric plate 40, each of the metal sheets 30 overlapping with one of the metal holes 41.

[0043] In some alternative embodiments, a plurality of metal holes 41 are symmetrically distributed along the centerline of the microstrip line 10, so that when the microstrip lines 10 of the two interconnect structures are overlapped, the metal sheets 30 of the two interconnect structures correspond one-to-one.

[0044] In some alternative embodiments, the signal hole 22 is a through hole with a metal plating on its wall, and the upper floor 50 has a through hole with a diameter larger than that which is not connected to the signal hole 22.

[0045] In some alternative embodiments, the shielding structure of the stripline 70 includes a grounding hole passing through the upper ground plane 50, the middle dielectric plate 60, the lower dielectric plate 80, and the lower ground plane 90, the inner wall of which has a metal plating.

[0046] In some alternative embodiments, the first upper dielectric plate 20 and the second upper dielectric plate 40 are rigid dielectric plates, and the middle dielectric plate 60 and the lower dielectric plate 80 are flexible dielectric plates.

[0047] Example: A rigid-flex plate interconnect structure was designed, such as... Figure 3 As shown, it operates in the Ka band, with the rigid plate made of Arlon CLTE-XT material and the flexible plate made of DuPont PI material. The design was simulated using the 3D electromagnetic simulation software HFSS.

[0048] a) In this rigid-flex interconnect structure, one port is as follows: Figure 1 As shown, the interconnect structure includes a flexible stripline 1 and a rigid microstrip line 2, with the other end of the interconnect structure having the same structure. The interconnect ports are stacked as follows: Figure 2 As shown, the components are microstrip line 10, upper dielectric substrate 20, EBG structure 30, upper dielectric substrate 40, upper ground plane 50, middle dielectric substrate 60, stripline 70, lower dielectric substrate 80, and lower ground plane 90.

[0049] b) The lower floor 90, lower dielectric plate 80, strip line 70, middle dielectric plate 60, and upper floor 50 constitute a flexible strip line, which achieves electromagnetic shielding through grounding holes 51, 61, 81, and 91.

[0050] c) The upper dielectric plate 20, the upper dielectric plate 40, the microstrip line 10, and the upper ground plate 50 constitute a rigid microstrip line.

[0051] d) The flexible stripline is converted into a rigid microstrip line after passing through signal holes 62, 42, and 22 and signal ground hole 52.

[0052] e) EBG structure 30 and EBG structure 41 constitute one end of EBG structure.

[0053] f) The microstrip line at the rigid plate port and the microstrip line at the inverted rigid plate port are attached together and fixed with screws through the mounting hole 21, thus achieving the interconnection between the rigid plate and the flexible plate.

[0054] The following table provides the main parameters of the embodiment.

[0055] Upper dielectric plate 20, 40 thickness 0.254mm Medium dielectric plate 60mm thickness 0.254mm Lower dielectric substrate 80mm thickness 0.254mm 70 width of strip 0.35mm Signal hole 42 diameter 0.24mm

[0056] 1. The EBG structure allows for greater tolerance to installation errors, reducing signal leakage and improving shielding effectiveness.

[0057] 2. It adopts screw fixing and signal line contact transmission method, eliminating the need for connectors, soldering, reducing costs, and enabling rapid interconnection.

[0058] 3. This invention can be widely applied to high-density three-dimensional rapid interconnection of microwave signals, such as conformal antennas, smart skins, wearable devices, etc.

[0059] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A high-shield rigid-flex plate rapid interconnection structure based on EBG, used to connect striplines (70) at two structural ports; Its features are, The interconnection structures at the two ports are identical, and the interconnection structure at one port includes: A strip line (70) is arranged between the intermediate dielectric plate (60) and the lower dielectric plate (80), and a lower floor (90) is arranged on the lower layer below the lower dielectric plate (80); An upper floor (50) arranged on the upper layer of the intermediate dielectric plate (60), a second upper dielectric plate (40) arranged on the upper layer of the upper floor (50), a first upper dielectric plate (20) arranged on the upper layer of the second upper dielectric plate (40); and a microstrip line (10) attached to the upper surface of the first upper dielectric plate (20). Among them, the microstrip line (10) is connected to the stripline (70) through the signal hole (22) passing through the first upper dielectric plate (20), the second upper dielectric plate (40), and the middle dielectric plate (60); both the microstrip line (10) and the stripline (70) are surrounded by shielding structures; During connection, the first upper dielectric substrate (20) of the interconnect structure at the two ports overlaps to make the microstrip lines (10) of the two interconnect structures overlap and conduct, and the interconnect structures are fixedly connected by fasteners.

2. The high-shield rigid-flex board rapid interconnect structure based on EBG as described in claim 1, characterized in that, The shielding structure of the microstrip line (10) includes a plurality of metal holes (41) with metal coatings on the walls of the second upper dielectric plate (40), and the plurality of metal holes (41) are distributed circumferentially around the microstrip line (10).

3. The high-shield rigid-flex board rapid interconnect structure based on EBG as described in claim 2, characterized in that, There are a plurality of metal sheets (30) between the first upper dielectric plate (20) and the second upper dielectric plate (40), each of the metal sheets (30) overlapping a metal hole (41).

4. The high-shield rigid-flex board rapid interconnect structure based on EBG as described in claim 3, characterized in that, Multiple metal holes (41) are symmetrically distributed along the centerline of the microstrip line (10), so that when the microstrip lines (10) of the two interconnect structures overlap, the metal sheets (30) of the two interconnect structures correspond one-to-one.

5. The high-shield rigid-flex board rapid interconnect structure based on EBG as described in claim 1, characterized in that, The signal hole (22) is a through hole with a metal plating on its wall, and the upper floor (50) has a through hole with a diameter larger than that which is not connected to the signal hole (22).

6. The high-shield rigid-flex board rapid interconnect structure based on EBG as described in claim 1, characterized in that, The shielding structure of the stripline (70) includes a grounding hole passing through the upper ground plane (50), the middle dielectric plate (60), the lower dielectric plate (80), and the lower ground plane (90), the inner wall of which has a metal plating.

7. The high-shield rigid-flex board rapid interconnect structure based on EBG as described in claim 1, characterized in that, The first upper dielectric plate (20) and the second upper dielectric plate (40) are rigid dielectric plates, while the middle dielectric plate (60) and the lower dielectric plate (80) are flexible dielectric plates.

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