Vertical interconnection structure and microwave system

Abstract

The invention discloses a vertical interconnection structure and a microwave system, and relates to the technical field of microwave circuits, the vertical interconnection structure comprises a multi-layer PCB structure and a coaxial transmission structure, the multi-layer PCB structure comprises a plurality of metal layers and dielectric layers, the metal layers comprise a top metal layer located at the top, at least one middle ground layer and a bottom metal layer, a transmission line and a top ground layer are arranged on the top metal layer, one end of the transmission line is arranged to be a connecting part in a bonding pad form, and a through hole is formed in the position, corresponding to the connecting part, of at least one middle ground layer close to the connecting part; the coaxial transmission structure comprises an outer conductor, an insulating sleeve and an inner conductor which are sequentially arranged in a sleeving mode, the outer conductor is detachably arranged on the multi-layer PCB structure, the outer conductor can be electrically connected with the top grounding layer in a contact mode, the inner conductor can be electrically connected with the connecting part in a contact mode, and the area of the butt joint face of the connecting part is larger than that of the butt joint face of the inner conductor. The invention aims to provide a detachable vertical interconnection structure.

Description

Vertical interconnect structure and microwave system Technical Field

[0001] This invention relates to the field of microwave circuit technology, and in particular to a vertical interconnect structure and a microwave system. Background Technology

[0002] With the rapid development of technologies such as 5G mobile communication, advanced phased array radar, high-speed signal transmission, and ultra-large-scale data centers, electronic systems are evolving towards higher frequencies, higher speeds, higher integration, and modularity. Furthermore, in cutting-edge systems such as 6G communication and high-speed data center interconnects, millimeter-wave bands have been widely adopted for core radio frequency (RF) frequencies. Against this backdrop, achieving efficient, reliable, and low-loss electrical connections between multi-layer functional sub-boards (such as RF front-end boards, digital signal processing boards, and power control boards) and RF devices has become one of the key bottlenecks in improving overall system performance. In the microwave and millimeter-wave RF fields, devices and feed structures typically employ planar transition structures such as microstrip lines, striplines, or coplanar waveguides. This approach facilitates interconnection operations such as wire bonding, but it poses a challenge to system miniaturization. Therefore, to improve the integration of RF systems, vertical interconnect structures have become the preferred choice.

[0003] An ideal vertical interconnect architecture requires several core characteristics across a wide bandwidth, from DC to microwave and even millimeter-wave frequencies. First, superior RF performance is fundamental, including low insertion loss, low return loss, stable characteristic impedance (typically 50 ohms), and high channel isolation to ensure signal integrity. Second, modularity is essential for maintainability, such as supporting rapid insertion and replacement of daughterboards, simplifying system debugging, upgrades, and maintenance processes, and reducing total lifecycle costs. Finally, the architecture must be adaptable to the layout and routing requirements of modern high-density interconnect PCBs, enabling vertical transitions of numerous I / O signals within a limited area and providing high-density integration capabilities.

[0004] Currently, the coaxial-like permanent interconnect structures used in the industry typically achieve electrical and mechanical fixation through soldering or micromachining processes, offering the advantage of high integration. However, these structures are not detachable and have poor maintainability. Summary of the Invention

[0005] The main objective of this invention is to propose a vertical interconnect structure and a microwave system, with the aim of providing a detachable vertical interconnect structure.

[0006] To achieve the above objectives, the present invention proposes a vertical interconnect structure, wherein the vertical interconnect structure includes: a multilayer PCB structure, including multiple metal layers and a dielectric layer disposed between two adjacent metal layers, wherein the multiple metal layers include a top metal layer at the top, at least one intermediate ground layer, and a bottom metal layer, wherein a transmission line is disposed on the top metal layer and a top ground layer located around the transmission line, wherein one end of the transmission line located in the middle of the top metal layer is configured as a connection portion in the form of a pad, and at least one intermediate ground layer near the connection portion has a through hole corresponding to the position of the connection portion; and a coaxial transmission structure, including an outer conductor, an insulating sleeve, and an inner conductor sequentially sleeved, wherein the outer conductor is detachably disposed on the multilayer PCB structure and can make contact and electrical connection with the top ground layer, and the inner conductor can make contact and electrical connection with the connection portion, wherein the mating surface area of ​​the connection portion is larger than the mating surface area of ​​the inner conductor, and wherein, when making contact and electrical connection, the end of the inner conductor is located inside the connection portion.

[0007] In one embodiment, the mating surfaces of the connecting portion and the inner conductor are set to be circular, and the radius of the mating surface of the connecting portion is A, and the radius of the mating surface of the inner conductor is a, then 0.15mm≤Aa.

[0008] In one embodiment, the transmission line is provided with an impedance transformation structure that connects to the connection portion.

[0009] In one embodiment, the impedance transformation structure includes multiple impedance transformation segments of different widths located on the transmission line.

[0010] In one embodiment, the coaxial transmission structure includes a main body with a mounting hole, an insulating sleeve and an inner conductor disposed in the mounting hole, and the main body is plated with a metal plating layer, which forms the outer conductor.

[0011] In one embodiment, the inner conductor and the insulating sleeve are detachably disposed on the main body.

[0012] In one embodiment, the inner conductor comprises a wool button.

[0013] In one embodiment, a clearance groove is provided at the bottom of the outer conductor corresponding to the position of the transmission line.

[0014] In one embodiment, a plurality of metallized vias with grounding structures are provided between the plurality of metal layers, the plurality of metallized vias are distributed circumferentially along the transmission line, and an opening is formed at the other end of the transmission line.

[0015] The present invention also proposes a microwave system, wherein the microwave system includes: a vertical interconnect structure, comprising a multilayer PCB structure and a coaxial transmission structure, the multilayer PCB structure including multiple metal layers and a dielectric layer disposed between two adjacent metal layers, and the multiple metal layers including a top metal layer at the top, at least one intermediate ground layer and a bottom metal layer, the top metal layer having a transmission line and a top ground layer located around the transmission line, one end of the transmission line located in the middle of the top metal layer being configured as a connection portion in the form of a pad, and at least one intermediate ground layer near the connection portion having a through hole corresponding to the position of the connection portion; the coaxial transmission structure includes an outer conductor, an insulating sleeve and an inner conductor sequentially sleeved, the outer conductor being detachably disposed on the multilayer PCB structure and capable of contacting and electrically connecting with the top ground layer, the inner conductor being capable of contacting and electrically connecting with the connection portion, the mating surface area of ​​the connection portion being larger than the mating surface area of ​​the inner conductor, and when contacting and electrically connecting, the end of the inner conductor being located within the connection portion.

[0016] In one embodiment, the microwave system further includes: a microwave circuit electrically connected to the coaxial transmission structure; or, a terminal antenna coupled to the coaxial transmission structure, wherein the outer conductor is detachably disposed or integrally disposed on the terminal antenna.

[0017] In the technical solution of this invention, vertical interconnection is achieved by the multilayer PCB structure and the coaxial transmission structure. Specifically, the outer conductor is detachably disposed on the multilayer PCB structure, while the inner conductor is electrically connected to the connection portion of the transmission line on the multilayer PCB structure. To ensure the reliability of the contact connection and guarantee good contact between the two, this application sets the contact surface area of ​​the connection portion to be larger than the contact surface area of ​​the inner conductor. At the same time, the through hole is opened on the intermediate ground layer near the connection portion to effectively offset the high-frequency parasitic capacitance effect at the connection between the inner conductor and the connection portion, thereby achieving high-frequency broadband impedance matching. This realizes the detachable connection scheme of the vertical interconnection structure. Attached Figure Description

[0018] 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 the structures shown in these drawings without creative effort.

[0019] Figure 1 is a perspective view of a three-dimensional structure of an embodiment of the vertical interconnect structure provided by the present invention; Figure 2 is a perspective view of a planar structure of Figure 1; Figure 3 is an exploded view of the structure of Figure 1; Figure 4 is an exploded view of the coaxial transmission structure in Figure 1; Figure 5 is a perspective view of a three-dimensional structure of a multilayer PCB structure in Figure 1; Figure 6 is an exploded view of the multilayer PCB structure in Figure 5; Figure 7 is a structural diagram of the connection between the outer conductor and the connecting part provided by the present invention; Figure 8 is a comparative structural diagram of a small connection area of ​​the connecting part and no through holes in the intermediate ground layer; Figure 9 is a comparative structural diagram of a large connection area of ​​the connecting part and no through holes in the intermediate ground layer; Figure 10 is a comparison diagram of the transmission performance of the vertical interconnect structures provided in Figures 7, 8, and 9.

[0020] Explanation of reference numerals: 100, Vertical interconnect structure; 1, Multilayer PCB structure; 11, Top metal layer; 11a, Transmission line; 11b, Top ground layer; 111, Connection section; 112, Impedance transformation structure; 112a, Impedance transformation section; 12, Intermediate ground layer; 121, Through-hole; 13, Bottom metal layer; 14, Dielectric layer; 15, Metallized via; 2, Coaxial transmission structure; 21, Outer conductor; 211, Clearance groove; 22, Insulating sleeve; 23, Inner conductor.

[0021] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0024] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0025] With the rapid development of technologies such as 5G mobile communication, advanced phased array radar, high-speed signal transmission, and ultra-large-scale data centers, electronic systems are evolving towards higher frequencies, higher speeds, higher integration, and modularity. Furthermore, in cutting-edge systems such as 6G communication and high-speed data center interconnects, millimeter-wave bands have been widely adopted for core radio frequency (RF) frequencies. Against this backdrop, achieving efficient, reliable, and low-loss electrical connections between multi-layer functional sub-boards (such as RF front-end boards, digital signal processing boards, and power control boards) and RF devices has become one of the key bottlenecks in improving overall system performance. In the microwave and millimeter-wave RF fields, devices and feed structures typically employ planar transition structures such as microstrip lines, striplines, or coplanar waveguides. This approach facilitates interconnection operations such as wire bonding, but it poses a challenge to system miniaturization. Therefore, to improve the integration of RF systems, vertical interconnect structures have become the preferred choice.

[0026] An ideal vertical interconnect architecture requires several core characteristics across a wide bandwidth, from DC to microwave and even millimeter-wave frequencies. First, superior RF performance is fundamental, including low insertion loss, low return loss, stable characteristic impedance (typically 50 ohms), and high channel isolation to ensure signal integrity. Second, modularity is essential for maintainability, such as supporting rapid insertion and replacement of daughterboards, simplifying system debugging, upgrades, and maintenance processes, and reducing total lifecycle costs. Finally, the architecture must be adaptable to the layout and routing requirements of modern high-density interconnect PCBs, enabling vertical transitions of numerous I / O signals within a limited area and providing high-density integration capabilities.

[0027] Currently, the industry commonly uses multilayer board vertical interconnect solutions, including coaxial permanent interconnects (such as ball grid arrays, photolithography, electroplating, and LTCC integrated molding), cavity substrate integrated waveguides (ESIW), and flexible probes (PogoPin). Cavity substrate integrated waveguides can be assembled from multiple layers of boards, offering advantages such as high quality factor, low transmission loss, high power capacity, and good shielding. However, the physical size of this structure is significantly larger than structures like microstrip lines, and it exhibits waveguide frequency cutoff characteristics, resulting in a relatively narrow bandwidth. Furthermore, its design process is complex and sensitive to manufacturing precision and substrate material properties, all of which limit its wider application. Flexible contact interconnect structures offer a degree of detachability and tolerance compensation, facilitating testing and insertion / removal. However, their typical internal helical springs or cantilever beam structures exhibit strong parasitic effects at high frequencies, severely restricting their high-frequency response. Additionally, achieving good shielding typically requires a complex external metal shell, limiting its integration density. For coaxial-like permanent interconnect structures, electrical and mechanical fixation is typically achieved through soldering or micromachining processes, offering the advantage of high integration. However, these structures are not removable, and any failure of a single board will lead to difficult repairs, or even the scrapping of the entire module, resulting in high time and economic costs.

[0028] In view of this, the present invention proposes a vertical interconnection structure. Please refer to Figures 1 to 3 for embodiments of the vertical interconnection structure proposed in this application. The vertical interconnection structure will be described in detail below with reference to the specific figures.

[0029] Please refer to Figures 1 to 3. The vertical interconnect structure 100 includes a multilayer PCB structure 1 and a coaxial transmission structure 2. The multilayer PCB structure 1 includes multiple metal layers and a dielectric layer 14 disposed between two adjacent metal layers. The multiple metal layers include a top metal layer 11 at the top, at least one intermediate ground layer 12, and a bottom metal layer 13. A transmission line 11a and a top ground layer 11b located around the transmission line 11a are disposed on the top metal layer 11. One end of the transmission line 11a located in the middle of the top metal layer 11 is configured as a pad-shaped connection portion 111. At least one The intermediate grounding layer 12 near the connection portion 111 has a through hole 121 corresponding to the position of the connection portion 111; the coaxial transmission structure 2 includes an outer conductor 21, an insulating sleeve 22 and an inner conductor 23 sequentially sleeved. The outer conductor 21 is detachably disposed on the multilayer PCB structure 1 and can be electrically connected to the top grounding layer 11b. The inner conductor 23 can be electrically connected to the connection portion 111. The mating surface area of ​​the connection portion 111 is larger than the mating surface area of ​​the inner conductor 23, and when electrically connected, the end of the inner conductor 23 is located inside the connection portion 111.

[0030] In the technical solution of the present invention, the multilayer PCB structure 1 and the coaxial transmission structure 2 are vertically interconnected. Specifically, the outer conductor 21 is detachably disposed on the multilayer PCB structure 1, and the inner conductor 23 is electrically connected to the connection portion 111 of the transmission line 11a on the multilayer PCB structure 1. To ensure the reliability of the contact connection and to ensure good contact between the two, the contact surface area of ​​the connection portion 111 is set to be larger than the contact surface area of ​​the inner conductor 23. At the same time, the through hole 121 is opened on the intermediate ground layer 12 near the connection portion 111 to effectively offset the high-frequency parasitic capacitance effect at the connection between the inner conductor 23 and the connection portion 111, and to achieve high-frequency broadband impedance matching. Thus, the detachable connection scheme of the vertical interconnect structure 100 is realized. For details, please refer to Figures 7, 8, and 9, which correspond to three comparative examples of the connection part 111 having different mating surface areas and whether the intermediate grounding layer 12 has the through hole 121. Figure 7 shows the connection part 111 having a larger mating surface area and the intermediate grounding layer 12 having the through hole 121, which is an embodiment of this application. Figure 8 shows the connection part 111 having a smaller mating surface area and the intermediate grounding layer 12 not having the through hole 121, which is one example. Figure 9 shows the connection part 111 having a larger mating surface area and the intermediate grounding layer 12 not having the through hole 121, which is another example. Referring to Figure 10, it is a comparison chart of the transmission performance of the vertical interconnection structure 100 obtained by simulation using the above three comparative examples.

[0031] Furthermore, referring to Figure 6, it can be understood that the basic signal transmission function of the multilayer PCB structure 1 is essentially the signal transmission process between the transmission line 11a, the top ground layer 11b, and the intermediate ground layer 12. However, considering the structural strength and reliability of the multilayer PCB structure 1, the multiple metal layers also include a bottom metal layer 13 located at the bottom of the multilayer PCB structure 1, and correspondingly, a dielectric layer 14 located between the bottom metal layer 13 and the intermediate ground layer 12. Thus, structurally, the bottom metal layer 13 provides structural strength, preventing the multilayer PCB structure 1 from warping and ensuring the structural stability of the multilayer PCB structure 1. In terms of performance, the bottom metal layer 13 acts as a shielding layer, effectively suppressing external radiation and blocking external interference, thus ensuring system stability.

[0032] Specifically, the multilayer PCB structure 1 is a PCB structure formed by the overlapping of the metal layer and the dielectric layer 14. The top metal layer 11 includes the transmission line 11a and the top ground layer 11b located around the transmission line 11a, thereby forming a grounded coplanar waveguide structure. Combined with the intermediate ground layer 12 in the multilayer PCB structure 1 used to provide reference and shielding, it has better high-frequency performance and shielding. Specifically, the two ends of the transmission line 11a are the signal feed end and the signal feed end, respectively. In this application, the signal feed end of the transmission line 11a is set as the connection part 111 located in the middle of the top metal layer 11. The coaxial transmission structure 2 is connected to the multilayer PCB structure 1 to form the vertical interconnect structure 100. To meet the requirements of detachability and maintainability, the outer conductor 21 is detachably mounted on the multilayer PCB structure 1. This ensures a stable electrical connection between the outer conductor 21 and the top ground layer 11b. Since the inner conductor 23 is not fixedly connected to the transmission line 11a, to ensure assembly reliability and further guarantee good contact between the two, the mating surface area of ​​the connecting part 111 is set to be larger than the mating surface area of ​​the inner conductor 23, providing a certain assembly offset margin to meet the requirements of stable electrical connection. However, the increased mating area of ​​the connection portion 111 will increase the parasitic capacitance between it and the intermediate ground layer 12 in the multilayer PCB structure 1. At high frequencies, the current shunting effect is significant, severely reducing the local impedance and causing strong reflection. The impedance matching at high frequencies is severely deteriorated. Therefore, this application further proposes to set corresponding openings in the intermediate ground layer 12 near the connection portion 111 to increase the distance between the connection portion 111 and the metal layer, thereby reducing the increased parasitic capacitance due to the increased mating area of ​​the connection portion 111, optimizing impedance matching, and meeting the requirements of the detachable configuration scheme of the vertical interconnect structure 100.

[0033] It should be noted that the number of intermediate grounding layers 12 is not limited here, but depends on the actual setup requirements of the multilayer PCB structure 1. When there are multiple intermediate grounding layers 12, the number of intermediate grounding layers 12 with through holes 121 is also not limited, depending on the required distance between the actual connection part 111 and the bottom metal grounding layer. The intermediate grounding layers 12 within the required distance need to have through holes 121 to meet the structural and functional requirements.

[0034] Specifically, referring to Figure 7, in the embodiment of this application, the mating surfaces of the connecting portion 111 and the inner conductor 23 are set to be circular to facilitate the mating of the inner conductor 23 and the connecting portion 111. The radius of the mating surface of the connecting portion 111 is A, and the radius of the mating surface of the inner conductor 23 is a, then 0.15mm ≤ Aa. This limits the dimensional error value when the mating surface of the inner conductor 23 and the connecting portion 111 are mated, balancing the random errors and parasitic effects during the assembly and disassembly of the inner conductor 23 compensated by the enlarged connecting portion 111, thus meeting the structural and functional requirements. It is understood that in other embodiments, the specific dimensional settings between the two are not limited, as long as the enlarged connecting portion 111 can balance the random errors and parasitic effects during the assembly and disassembly of the inner conductor 23 compensated by the enlarged connecting portion 111.

[0035] Furthermore, referring to Figure 6, an impedance transformation structure 112 connecting the connection portion 111 is provided on the transmission line 11a. Adding the impedance transformation structure 112 connected to the connection portion 111 on the transmission line 11a significantly improves the broadband matching performance and design freedom of the vertical interconnect structure 100. This structure works in conjunction with the structural feature of the via 121 on the intermediate ground layer 12 described above, forming a composite matching network combining series (impedance transformation) and parallel (capacitive reactance cancellation). It can more accurately compensate for the complex parasitic inductance and residual capacitance introduced by the transition discontinuity between the inner conductor 23 and the connection portion 111, thereby adjusting the input impedance to the target value over a wider frequency range, further reducing the voltage standing wave ratio, reducing signal reflection, and achieving a flatter frequency response characteristic.

[0036] Specifically, the impedance transformation structure 112 includes multiple impedance transformation segments 112a of different widths located on the transmission line 11a. Introducing multiple impedance transformation segments 112a of different widths along the path from the transmission line 11a to the connection portion 111 essentially constructs a multi-section impedance step transformer, an improvement that enables more precise impedance gradient control. Each impedance transformation segment 112a, through its specific width (corresponding to a specific characteristic impedance) and length, compensates for impedance mismatch in different frequency bands. Cascading multiple segments can generate multiple precisely controlled resonant points within an ultra-wide frequency band, thus expanding the originally simple compensation into an optimized filter network with multiple degrees of freedom. This structure, in conjunction with the via 121 on the intermediate ground layer 12, can simultaneously and perfectly cancel the parallel parasitic capacitance of the vertical transition and smoothly transition the series parasitic inductance, ultimately achieving near-flat low reflection coefficient performance over an extremely wide frequency range. The specific number of impedance transformation segments 112a is set according to actual needs; in this embodiment, three impedance transformation segments 112a are used.

[0037] Furthermore, referring to Figure 4, the coaxial transmission structure 2 includes a main body with mounting holes. The insulating sleeve 22 and the inner conductor 23 are disposed in the mounting holes. The main body is plated with a metal plating layer, which forms the outer conductor 21. The form of the outer conductor 21 is not limited. For example, the main body described above can be used as the outer conductor 21. Changing the material of the main body can change the conductivity. However, it is understood that high conductivity will bring better performance. Using a high conductivity material to form the main body may result in high structural cost and poor structural stability. Considering that the current mainly flows on the surface of the mounting holes of the main body, this application adopts the form of plating a metal plating layer on the main body to utilize the metal plating layer to provide high conductivity and even oxidation resistance, thereby reducing the limitation on the material of the main body, facilitating the forming of the main body, and reducing structural cost.

[0038] Furthermore, the inner conductor 23 includes a fuzz button. The fuzz button is a cylindrical, elastic, conductive interconnect made of extremely fine, high-performance metal wires (such as gold-plated beryllium copper wire) through precision braiding or stamping. Due to the numerous tiny contact points operating in parallel within it, it exhibits near-coaxial electromagnetic characteristics and demonstrates excellent shielding and signal integrity, with outstanding insertion loss and return loss performance. In other words, the fuzz button possesses inherent advantages such as compact structure, compressibility, and ease of insertion and removal, making it suitable for the detachable connection requirements of this application. Moreover, this application proposes that the mating surface area of ​​the connecting portion 111 is larger than the mating surface area of ​​the inner conductor 23, ensuring good contact between the fuzz button and the connecting portion 111, thereby guaranteeing the performance of the inner conductor 23 using the fuzz button.

[0039] Furthermore, based on the detachable arrangement of the coaxial transmission structure 2 and the multilayer PCB structure 1 to improve maintainability, the inner conductor 23 is further detachably disposed on the insulating sleeve 22, and the insulating sleeve 22 is detachably disposed on the main body. This allows the inner conductor 23 and the insulating sleeve 22 to detach from the end of the coaxial transmission structure 2 connected to the multilayer PCB structure 1 when the coaxial transmission structure 2 is separated from the multilayer PCB structure 1, facilitating maintenance and replacement of the inner conductor 23 and the insulating sleeve 22. When the coaxial transmission structure 2 and the multilayer PCB structure 1 are fixedly connected, the inner conductor 23 can be electrically connected to the connecting part 111 and thus be limited, meeting the structural and functional requirements.

[0040] Furthermore, the outer conductor 21 is fixed to the multilayer PCB structure 1 so that while it is in contact with the top ground layer 11b, the outer conductor 21 cannot contact the transmission line 11a. The transmission line 11a is coplanar with the top ground layer 11b. Therefore, please refer to Figures 3 and 4. In this embodiment, a clearance groove 211 is provided at the bottom of the outer conductor 21 corresponding to the position of the transmission line 11a.

[0041] In addition, referring to Figures 5 and 6, multiple electrical interconnects are provided between the multiple metal layers. These multiple electrical interconnects are distributed circumferentially along the transmission line 11a, and an opening is formed at the other end of the transmission line 11a. The multiple electrical interconnects distributed circumferentially along the transmission line 11a, in this embodiment, utilize metallized vias 15 to form a high-performance electromagnetic shielding and signal isolation channel. This design allows the top metal layer 11, the intermediate ground layer 12, and the bottom metal layer 13 to form dense vertical interconnects along the sides of the signal path, thereby constructing a metallized shielding cavity that completely surrounds the transmission line 11a. This effectively suppresses signal radiation and external crosstalk, and ensures absolute consistency of the ground potential throughout the path, providing a stable basis for precise impedance control. The openings at the ends of the multiple electrical interconnects serve as a controllable signal interface, allowing signals to enter and exit the shielding channel in a controlled manner while maintaining overall shielding effectiveness. This combination of "full-coverage shielding" and "directional opening" enables the aforementioned broadband matching structure to operate in a near-ideal electromagnetic environment, strictly confining energy within the designed path, thereby achieving ultra-wideband, low-loss, and highly isolated vertical interconnect performance in actual systems that approaches the level of theoretical simulation.

[0042] The present invention also proposes a microwave system, which includes a vertical interconnection structure 100. The specific structure of the vertical interconnection structure 100 is as described in the above embodiments. Since the microwave system adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0043] Specifically, the end of the coaxial transmission structure 2 furthest from the multilayer PCB structure 1 can be a coupled terminal antenna structure for signal transmission, or it can be connected to other circuit structures to form a circuit system, depending on the requirements of the actual application scenario. That is, the microwave system described in this application also includes a microwave circuit or a terminal antenna. In some embodiments, the microwave circuit is electrically connected to the coaxial transmission structure 2, and in other embodiments, the terminal antenna is coupled to the coaxial transmission structure 2.

[0044] Specifically, in the embodiment where the terminal antenna is coupled to the coaxial transmission structure 2, the coaxial transmission structure 2 is detachably mounted on the multilayer PCB structure 1. The coaxial transmission structure 2 can be set independently of the terminal antenna or integrated into the terminal antenna, without limitation. Since the button is detached from the end of the outer conductor 21 connected to the multilayer PCB structure 1, the installation and removal of the button is not affected when the outer conductor 21 is integrated into the terminal antenna, thus meeting the structural and functional requirements. Moreover, the integrated mounting reduces processing steps, simplifies the structure, reduces the number of parts, lowers manufacturing costs, and is more practical.

[0045] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A vertical interconnection structure, characterized in that, include: A multilayer PCB structure includes multiple metal layers and a dielectric layer disposed between two adjacent metal layers. The multiple metal layers include a top metal layer at the top, at least one intermediate ground layer, and a bottom metal layer. A transmission line is disposed on the top metal layer, and a top ground layer is disposed around the transmission line. One end of the transmission line located in the middle of the top metal layer is configured as a connection portion in the form of a pad. At least one intermediate ground layer near the connection portion has a through-hole corresponding to the position of the connection portion. A coaxial transmission structure includes an outer conductor, an insulating sleeve, and an inner conductor sequentially disposed. The outer conductor is detachably disposed on the multilayer PCB structure and can make contact with the top ground layer. The inner conductor can make contact with the connection portion. The mating surface area of ​​the connection portion is larger than the mating surface area of ​​the inner conductor, and when making contact, the end of the inner conductor is located inside the connection portion.

2. The vertical interconnection structure as described in claim 1, characterized in that, The mating surfaces of the connecting part and the inner conductor are set to be circular, and the radius of the mating surface of the connecting part is A, and the radius of the mating surface of the inner conductor is a, then 0.15mm≤Aa.

3. The vertical interconnection structure as described in claim 1, characterized in that, The transmission line is provided with an impedance transformation structure that connects to the connection part.

4. The vertical interconnection structure as described in claim 3, characterized in that, The impedance transformation structure includes multiple impedance transformation segments of different widths located on the transmission line.

5. The vertical interconnection structure as described in claim 1, characterized in that, The coaxial transmission structure includes a main body with a mounting hole. The insulating sleeve and the inner conductor are disposed in the mounting hole. The main body is plated with a metal plating layer, which forms the outer conductor.

6. The vertical interconnection structure as described in claim 5, characterized in that, The inner conductor and the insulating sleeve are detachably mounted on the main body.

7. The vertical interconnection structure as described in claim 1, characterized in that, The inner conductor includes a wool button.

8. The vertical interconnection structure as described in claim 1, characterized in that, The bottom of the outer conductor has a clearance groove corresponding to the position of the transmission line.

9. The vertical interconnection structure as described in claim 1, characterized in that, Multiple metallized vias with grounding structures are provided between the multiple metal layers. The multiple metallized vias are distributed circumferentially along the transmission line and have an opening at the other end of the transmission line.

10. A microwave system, characterized in that, Includes the vertical interconnect structure as described in any one of claims 1-9.

11. The microwave system as claimed in claim 10, characterized in that, The microwave system further includes: a microwave circuit electrically connected to the coaxial transmission structure; or, a terminal antenna coupled to the coaxial transmission structure, wherein the outer conductor is detachably disposed or integrally disposed on the terminal antenna.

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