Signal transmission device and electronic equipment

Abstract

A signal transmission device and an electronic device, the signal transmission device comprising a first signal layer, a second signal layer and a plurality of connection layers located therebetween, the first signal layer comprising a first signal line and a first dielectric layer located adjacent to the connection layers, the second signal layer comprising a second signal line and a second dielectric layer located adjacent to the connection layers, the plurality of connection layers being provided with a signal transmission cavity having a first opening and a second opening located opposite to each other, a projection of one end of the first signal line on the connection layer at least partially overlapping with a projection of the first opening on the connection layer located adjacent to the first dielectric layer, and a projection of one end of the second signal line on the connection layer at least partially overlapping with a projection of the second opening on the connection layer located adjacent to the second dielectric layer. The signal transmission device transmits signals between the first signal line, the signal transmission cavity and the second signal line in a coupling manner, having a lower insertion loss and a higher bandwidth compared with a via manner.

Description

Technical Field

[0001] This application relates to the field of information transmission technology, and in particular to a signal transmission device and electronic device. Background Technology

[0002] In the field of communications, millimeter-wave frequencies have already been used in 5G mobile communications; in the field of intelligent driving sensors, millimeter-wave radar technology is very mature, and its market shipments are considerable, with a very high penetration rate in Europe. The development of wireless communication systems has promoted the miniaturization of front-end modules, meaning that more and more components can be placed within a limited space.

[0003] With the rapid development of millimeter-wave technology, the insertion loss of signals on PCBs (Printed Circuit Boards) or packaging substrates is crucial to overall performance. Insertion loss refers to the loss of load power at a point in the transmission system due to the insertion of components or devices; lower insertion loss is more beneficial for signal transmission. To reduce area and achieve high integration, signals need to be transmitted vertically from one layer to another, requiring low insertion loss for the transmission lines. For example, in a PCB, when a millimeter-wave signal is transmitted from one surface to another, through-layer routing is usually required. However, the insertion loss of conventional via designs for millimeter-wave signals is too high, leading to a significant degrade in overall RF performance. Summary of the Invention

[0004] This application provides a signal transmission device and electronic device for achieving low insertion loss and high bandwidth when realizing vertical signal transmission.

[0005] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0006] In a first aspect, this application provides a signal transmission device, including a first signal layer, a second signal layer, and a plurality of connecting layers located between the first signal layer and the second signal layer. The first signal layer includes a first signal line and a first dielectric layer, with the first signal line disposed away from the connecting layers relative to the first dielectric layer. The second signal layer includes a second signal line and a second dielectric layer, with the second signal line disposed away from the connecting layers relative to the second dielectric layer. A signal transmission cavity is provided in each of the plurality of connecting layers, and the signal transmission cavity is formed by the through-hole, the first signal layer, and the second signal layer. The first opening is located at one end of the through-hole adjacent to the first dielectric layer, and the second opening is located at one end of the through-hole adjacent to the second dielectric layer. When the cross-section of the signal transmission cavity is rectangular or circular, the area of ​​the first opening and the second opening is equal to the cross-sectional area of ​​the signal transmission cavity.

[0007] The orthographic projection of one end of the first signal line onto the connection layer at least partially overlaps with the orthographic projection of the first opening onto the connection layer, and the orthographic projection of one end of the second signal line onto the connection layer at least partially overlaps with the orthographic projection of the second opening onto the connection layer.

[0008] In this application, the first signal line and the second signal line are not on the same horizontal plane and are vertically separated. The first signal line is used to receive or transmit signals, and the second signal line is used to receive or transmit signals. The signals can be millimeter waves or terahertz waves. The frequency range of millimeter waves is 30-300 GHz, and the frequency range of terahertz waves is 100-10000 GHz.

[0009] In one embodiment, one end of the first signal line is a signal transmitting end, and one end of the second signal line is a signal receiving end. After receiving a signal through the first signal line, the signal transmission device radiates the signal from the signal transmitting end of the first signal line to the first opening and then into the signal transmission cavity. The signal is then output from the second opening and received by the signal receiving end of the second signal line, and subsequently transmitted through the second signal line. In some embodiments, one end of the first signal line is a signal receiving end, and one end of the second signal line is a signal transmitting end. After receiving a signal through the second signal line, the signal transmission device radiates the signal from the signal transmitting end of the second signal line to the second opening and then into the signal transmission cavity. The signal is then output from the first opening and received by the signal receiving end of the first signal line, and subsequently transmitted through the first signal line. In the following embodiments, unless otherwise specified, the signal transmission process is illustrated using the first signal line receiving the signal and the second signal line transmitting the signal as examples.

[0010] In some implementations, when the first signal line, the signal transmission cavity, and the second signal line are parallel to each other, the first opening and the second opening are aligned in parallel, with one end of the first signal line above the first opening and one end of the second signal line below the second opening.

[0011] The first signal line can be attached to or coated on the surface of the first dielectric layer away from the interconnect layer. During fabrication, the first signal layer is first pressed onto the surface of the interconnect layer, and then the metal sheet of the first signal layer away from the interconnect layer surface is patterned to form the first signal line. The fabrication method of the second signal layer can be the same as that of the first signal layer. In this application, the dielectric layer is an insulating dielectric layer; for example, if the first dielectric layer and the second dielectric layer are insulating dielectric layers, signal interference between the layers is avoided.

[0012] The connecting layers can be either PP layers or core layers. Multiple connecting layers include multiple PP layers and multiple core layers. The number of PP layers and core layers is not limited in this application and can be set according to actual needs. The first dielectric layer is a PP layer made of polypropylene; the second dielectric layer is also a PP layer.

[0013] The signal transmission device of this application transmits a signal from a first signal line to one end of the first signal line, then transmits it to a signal transmission cavity by energy radiation at one end of the first signal line, and then couples it to a second signal line via the signal transmission cavity, and then transmits it to other electronic components from the second signal line. The signal transmission cavity is not directly connected to the first signal line and the second signal line, respectively. The signal is conducted through circuits on the first signal line and the second signal line, and the signal is transmitted between the first signal line and the second signal line by coupling. Compared with the via method, this transmission method has a lower insertion loss value and a higher bandwidth when transmitting millimeter wave and higher frequency band signals.

[0014] Specifically, when using vias to transmit signals, a first pad is provided around one end of the via, and the first signal line is directly connected to the first pad. The first pad is connected to the copper layer on the inner wall of the via. The other end of the via has a second pad, which is connected to the second signal line. The signal is transmitted from the first signal line, the first pad, the via, and the second pad to the second signal line. In the millimeter-wave band, due to the parasitic effects of the circuit, the parasitic circuit of the signal via is very complex. For example, factors such as the size of the first pad, the size of the via, and the size of the second pad all affect impedance matching. When the impedance matching is adjusted by adjusting the above factors, the signal transmission performance is quite sensitive to these factors, making it difficult to achieve impedance adjustment, resulting in poor impedance matching and severely degraded transmission performance.

[0015] When the coupling method of this application is used for transmission, when the signal emitted by the first signal line is transmitted through the signal transmission cavity, the waveguide mode in a specific frequency band is excited by adjusting the cavity size, so that the signal transmission cavity becomes a waveguide that can transmit signals in that specific frequency band; and the adjustment of the cavity size is not sensitive to the transmission performance, so the signal transmission device of this application can have advantages such as high bandwidth and low insertion loss.

[0016] Furthermore, in this application, a first signal line and a second signal line are arranged on both sides of the signal transmission cavity. The first signal line is used to transmit signals output by other electronic components, and the signal is emitted from one end of the first signal line. After the signal completes transmission in the vertical direction, the signal is received by the second signal line, and the second signal line transmits the signal to other electronic components. In this application, signal lines are arranged on both sides of the signal transmission cavity for circuit signal transmission. The signal transmission cavity is used for transmission in the vertical interconnection part, realizing signal transmission between the first signal line on the surface of the signal transmission device and the second signal line on the bottom layer, which can reduce the vertical transmission loss of the signal.

[0017] When the signal transmission device is a chip packaging substrate, the first signal line may be disposed adjacent to the die relative to the second signal line. In some embodiments, the second signal line may be disposed adjacent to the die relative to the first signal line.

[0018] In one possible implementation, a shielding layer is provided on the inner wall of the signal transmission cavity, and the signal transmission cavity is filled with a signal transmission medium. The shielding layer serves to prevent signals propagating within the signal transmission cavity from leaking out from the inner wall, thus ensuring signal transmission efficiency. It also shields the signal transmission cavity from external wireless signal radiation that could interfere with signal transmission within it. The shielding layer can be made of copper, aluminum, or iron, or other materials capable of shielding signals.

[0019] The signal transmission medium can be selected based on the actual product. In some embodiments, the signal transmission medium can be air, meaning that the signal is transmitted through air, which has an extremely low dielectric loss factor. In some embodiments, the signal transmission medium can also be a semi-solid or solid transmission medium. The semi-solid transmission medium can be ink, and other materials can be selected according to the characteristics of the signal and the transmission requirements. Furthermore, the parameters of the signal transmission medium can be designed according to actual needs, with preference given to materials with lower dielectric loss factors to minimize signal transmission loss in the signal transmission cavity. For signal transmission cavities with air as the signal transmission medium, the signal transmission device is prone to deformation when subjected to pressure. Moreover, if the signal transmission cavity is not filled with signal transmission medium or is not fully filled, the PP layer medium flow in the first and second dielectric layers will be uneven during the pressing process between the first and second signal layers and the signal transmission cavity, leading to delamination and affecting interlayer adhesion. In contrast, signal transmission cavities filled with semi-solid or solid transmission media have stronger structural strength, are less prone to deformation, and can avoid delamination problems.

[0020] In one possible implementation, the first signal layer further includes multiple first shielding elements, which are horizontally arranged around the signal transmission cavity and the end of the first signal line near the signal transmission cavity. "Horizontally surrounding" means that the orthographic projection of the first shielding element on the connecting layer surrounds the orthographic projection of the signal transmission cavity and the end of the first signal line near the signal transmission cavity on the connecting layer. The first shielding elements prevent the signal emitted by the first signal line from radiating out of the plane containing the first signal layer, allowing the signal emitted by the first signal line to radiate into the signal transmission cavity with greater efficiency. The first shielding element can be a metal sheet, a metal pillar, or a via. The metal can be one of copper, aluminum, or iron, or other materials capable of shielding signals. The via includes blind vias or through-holes; in this embodiment, the first shielding element is a blind via. When the first shielding element is a through-hole, it must be positioned away from the second signal line to avoid penetrating it.

[0021] In one possible implementation, the first shielding element is arranged in a sheet-like form, with one surface of the first shielding element facing the signal transmission cavity and the first signal line to increase the signal shielding area. The number of first shielding elements is not limited and can be set according to actual needs. The smaller the gap between two adjacent first shielding elements, the better the shielding effect. In one possible implementation, the gap between two adjacent first shielding elements is less than 1 / 4 of the signal wavelength to reduce radiation loss.

[0022] In some embodiments, multiple first shielding elements may be arranged horizontally around the signal transmission cavity, meaning that the orthographic projection of the first shielding element on the connecting layer surrounds the orthographic projection of the signal transmission cavity on the connecting layer. In some embodiments, there may be only one first shielding element, and this first shielding element is arranged horizontally around the signal transmission cavity and the end of the first signal line closest to the signal transmission cavity. That is, in this embodiment, the first shielding element is a single, seamless structural component.

[0023] In one possible implementation, the first signal layer further includes a first conductive layer, which is disposed on the same side of the first dielectric layer as the first signal line, and the first conductive layer and the first signal line are spaced apart. A first shield penetrates through the first conductive layer and the first dielectric layer. The first conductive layer is grounded. The first conductive layer and the first signal layer can be simultaneously formed on the same side of the first dielectric layer; for example, a metal layer can be formed on one side of the first dielectric layer, and then the metal layer can be patterned to form the first signal line and the first conductive layer. In some embodiments, the first shield also extends to the interconnect layer.

[0024] In one possible implementation, the second signal layer includes a plurality of second shielding members, which are horizontally arranged around the signal transmission cavity and the end of the second signal line near the signal transmission cavity. Specifically, the orthographic projection of the second shielding members on the connecting layer is arranged around the orthographic projection of the end of the second signal line near the signal transmission cavity on the connecting layer.

[0025] The second shielding element prevents signals radiated from the signal transmission cavity from radiating out of the second signal layer, ensuring that the signals radiated from the signal transmission cavity can be radiated to the second signal line and received by the second signal line with greater efficiency. The second shielding element can be a metal sheet, a metal pillar, or a via. The metal can be one of copper, aluminum, or iron, or other materials capable of shielding signals. The via can include blind vias or through-holes; in this embodiment, the second shielding element is a blind via. When the second shielding element is a through-hole, it must be positioned away from the first signal line to avoid penetrating it.

[0026] In one possible implementation, the second shield is arranged in a sheet-like form, with one surface of the second shield facing the signal transmission cavity and the second signal line to increase the signal shielding area. The number of second shields is not limited and can be set according to actual needs. The smaller the gap between two adjacent second shields, the better the shielding effect. In one possible implementation, the gap between two adjacent second shields is less than 1 / 4 of the signal wavelength to reduce radiation loss.

[0027] In some embodiments, multiple second shielding elements may be arranged horizontally around the signal transmission cavity, meaning that the orthographic projection of the second shielding element on the connecting layer surrounds the orthographic projection of the signal transmission cavity on the connecting layer. In some embodiments, there may be only one second shielding element, and this second shielding element is arranged horizontally around the signal transmission cavity and the end of the second signal line near the signal transmission cavity. That is, in this embodiment, the second shielding element is a single, seamless structural component.

[0028] In one possible implementation, the second signal layer further includes a second conductive layer, which is disposed on the same side of the second dielectric layer as the second signal line, and the second conductive layer and the second signal line are spaced apart. A second shield penetrates both the second conductive layer and the second dielectric layer. The second conductive layer is grounded. The second conductive layer and the second signal line can be simultaneously formed on the same side of the second dielectric layer; for example, a metal layer can be formed on one side of the second dielectric layer, and then the metal layer can be patterned to form the second signal line and the second conductive layer. In some embodiments, the second shield also extends to the connection layer.

[0029] In one possible implementation, the signal transmission device further includes a first shielding cover. The first shielding cover is disposed on the side of the first signal line away from the signal transmission cavity and is insulated from the first signal line. The orthographic projection of the first shielding cover onto the connecting layer at least covers the first opening of the signal transmission cavity. The first shielding cover serves two purposes: firstly, it prevents the signal emitted by the first signal line from radiating away from the side of the first signal line away from the signal transmission cavity, thereby reducing loss; secondly, it prevents external wireless signals from entering the signal transmission cavity and interfering with signal transmission within the cavity. In one embodiment, the first shielding cover includes a top wall and a peripheral wall. A notch is provided in the peripheral wall through which the first signal line passes to avoid electrical connection between the first signal line and the first shielding cover. In some embodiments, an insulating layer is provided between the first shielding cover and the first signal line to insulate them from each other. The first shielding cover may be a copper layer.

[0030] In one possible implementation, the signal transmission device further includes a second shielding cover. The second shielding cover is disposed on the side of the second signal line away from the signal transmission cavity and is insulated from the second signal line. The orthographic projection of the second shielding cover onto the connecting layer at least covers the second opening of the signal transmission cavity. The second shielding cover serves two purposes: firstly, it prevents signals radiated from the signal transmission cavity from radiating away from the side of the second signal line away from the signal transmission cavity, allowing the signal to be effectively radiated to the second signal line, improving signal coupling efficiency, and reducing signal loss; secondly, it prevents external wireless signals from interfering with signal transmission within the signal transmission cavity. Alternatively, the second shielding cover may have a notch in its peripheral wall through which the second signal line passes to avoid electrical connection between the second signal line and the second shielding cover. In some embodiments, an insulating layer is provided between the second shielding cover and the second signal line to insulate them from each other.

[0031] In one possible implementation, the signal transmission device further includes a first signal array connected to one end of the first signal line, and its orthographic projection onto the signal transmission cavity is located within the signal transmission cavity. The first signal array increases the area of ​​the first signal line for transmitting or receiving signals, thereby improving the signal transmission efficiency between the first and second signal lines. In this embodiment, the first signal array is a copper layer; in some embodiments, the material of the first signal array can also be aluminum or iron. The shape and specific dimensions of the first signal array can be set according to the signal transmission efficiency and actual product requirements, and are not limited in this application.

[0032] In some implementations, the first signal element can be printed together with the first signal line, or a copper sheet can be attached as the first signal element to one end of the first signal line adjacent to the signal transmission cavity.

[0033] In one possible implementation, the signal transmission device further includes a first signal element located between the first signal line and the second signal line, with its orthographic projection onto the signal transmission cavity located within the signal transmission cavity. In some embodiments, the first signal element is located on the surface of the first dielectric layer away from the first signal line, and is disposed adjacent to the first opening to improve the signal transmission efficiency between the first and second signal lines. In other embodiments, the first signal element can be located at any position between the first and second signal lines, and can be located within the cavity of the signal transmission cavity. When located within the cavity, the signal transmission medium of the signal transmission cavity is semi-solid or solid, so that the first signal element is fixed within the signal transmission medium. In still other embodiments, the first signal element is located on the surface of the second dielectric layer away from the second signal line to improve the signal transmission efficiency between the first and second signal lines.

[0034] In one embodiment, the first signal layer further includes a third conductive layer and a third dielectric layer. The third conductive layer is disposed on the side of the first dielectric layer away from the first signal line. The third dielectric layer is disposed between multiple interconnect layers and the third conductive layer. The orthographic projection of the third conductive layer onto the interconnect layers does not overlap with the orthographic projection of the signal transmission cavity onto the interconnect layers. In this embodiment, the first signal layer includes a core layer and a PP layer. The core layer is disposed away from the interconnect layers relative to the PP layer. The first signal line and the first conductive layer are patterned metal sheets on one surface of the core layer, and the third conductive layer and the first signal element are patterned metal sheets on the other surface of the core layer. The PP layer is the third dielectric layer. In some embodiments, the second signal layer includes a core layer and a PP layer.

[0035] In one possible implementation, the first signal element can be disposed on the side of the first dielectric layer away from the interconnect layer, or it can be disposed between the first dielectric layer and the third dielectric layer. In this embodiment, the first signal element is disposed between the first dielectric layer and the third dielectric layer, the first signal element is spaced apart from the third conductive layer, and its orthographic projection on the signal transmission cavity is located inside the signal transmission cavity.

[0036] In one possible implementation, the signal transmission device further includes a second signal element connected to one end of the second signal line, and its orthographic projection onto the signal transmission cavity lies within the signal transmission cavity. The second signal element increases the area of ​​the second signal line for transmitting or receiving signals, thereby improving the signal transmission efficiency between the first and second signal lines. In some embodiments, the signal transmission device includes both a first signal element and a second signal element, respectively increasing the signal transmission area of ​​the first and second signal lines, thereby improving the signal transmission efficiency between the first and second signal lines and reducing losses.

[0037] In one possible implementation, the signal transmission device is further provided with grounding holes penetrating the first signal layer, the second signal layer, and multiple connection layers; the grounding holes are horizontally arranged around the side of the first shield away from the signal transmission cavity, the first signal line, and the second signal line. The number of grounding holes is not limited and can be set according to actual needs.

[0038] In one possible implementation, at least one first connection sublayer is further provided between the first signal layer and the connection layer. The first connection sublayer can be a core layer or a PP layer. When the first connection sublayer is a PP layer, it can cover the first opening of the signal transmission cavity. When the first connection sublayer is a core layer, the orthographic projection of the metal sheet in the core layer onto the connection layer does not overlap with the orthographic projection of the first opening onto the connection layer, to prevent signals radiated from the first signal line from being shielded by the metal sheet in the first connection sublayer and thus unable to radiate into the signal transmission cavity. In some embodiments, the multiple first connection sublayers include multiple core layers and multiple PP layers arranged in an alternating manner.

[0039] In some embodiments, at least one second connection sublayer is further provided between the second signal layer and the connection layer. The second connection sublayer can be a core layer or a PP layer. When the second connection sublayer is a PP layer, it can cover the second opening of the signal transmission cavity. When the second connection sublayer is a core layer, the orthographic projection of the metal sheet in the core layer onto the connection layer does not overlap with the orthographic projection of the second opening onto the connection layer, to prevent signals radiated from the signal transmission cavity from being shielded by the metal sheet in the second connection sublayer and thus unable to radiate to the second signal line. In some embodiments, the multiple second connection sublayers include multiple core layers and multiple PP layers arranged in an alternating manner.

[0040] In one possible implementation, at least one first cover layer is provided on the side of the first signal layer away from the connection layer. The first cover layer can be a core layer or a PP layer. In some embodiments, other electronic devices or functional circuits can also be disposed on the surface of the first cover layer away from the first signal layer, but electronic devices or functional circuits that will not affect the signal transmission between the first signal line and the second signal line are preferred.

[0041] In some embodiments, at least one second cover layer is provided on the side of the second signal layer away from the connection layer. The second cover layer can be a core layer or a PP layer. In some embodiments, other electronic devices or functional circuits can also be disposed on the surface of the second cover layer away from the second signal layer, but electronic devices or functional circuits that will not affect the signal transmission between the first signal line and the second signal line are preferred.

[0042] In one possible implementation, the signal transmission device further includes a first signal element disposed at one end of the first signal line, and a first covering layer located on the surface of the first signal line and the first signal element away from the connecting layer. In some embodiments, the signal transmission device further includes a second signal element disposed at one end of the second signal line, and a second covering layer located on the surface of the second signal line and the second signal element away from the connecting layer.

[0043] In one possible implementation, the signal transmission device further includes a first shielding cover, with the first covering layer located on the side of the first signal layer away from the connection layer and covering the first shielding cover. In some embodiments, the signal transmission device further includes a second shielding cover, with the second covering layer located on the side of the second signal layer away from the connection layer and covering the second shielding cover.

[0044] In one possible implementation, the signal transmission device is a circuit board.

[0045] In one possible implementation, the signal transmission device is a chip packaging substrate.

[0046] Secondly, this application provides an electronic device, which includes a middle frame, a back cover, a chip located between the middle frame and the back cover, and a signal transmission device as described above. The chip is disposed on the signal transmission device and is electrically connected to the signal transmission device.

[0047] Thirdly, this application provides an electronic device, which includes a mid-frame, a back cover, and a motherboard and a chip located between the mid-frame and the back cover. The chip is disposed on the motherboard and includes a die and a signal transmission device as described above. The die is disposed on one side of the signal transmission device and is electrically connected to the signal transmission device. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the structure of an electronic device provided in one embodiment of this application;

[0049] Figure 2 This is a schematic diagram of a PCB with a chip provided in one embodiment of this application;

[0050] Figure 3 This is a schematic diagram of the structure of a chip provided in one embodiment of this application;

[0051] Figure 4a This is a top view of a signal transmission device provided in one embodiment of this application;

[0052] Figure 4b yes Figure 4a Sectional view along line AA;

[0053] Figure 4c This is a top view of multiple connection layers in a signal transmission device provided in one embodiment of this application;

[0054] Figure 4d yes Figure 4b Sectional view along line BB;

[0055] Figure 5a This is a top view of a signal transmission device provided in one embodiment of this application;

[0056] Figure 5b This is a bottom view of a signal transmission device provided in one embodiment of this application;

[0057] Figure 6a This is a schematic diagram of the orthographic projection of the first signal line and the second signal line on the connection layer in a signal transmission device provided in an embodiment of this application;

[0058] Figure 6b This is a schematic diagram of the orthographic projection of the first signal line and the second signal line on the connection layer in a signal transmission device provided in an embodiment of this application;

[0059] Figure 7 This is a schematic diagram of the structure of a signal transmission device with a via provided in one embodiment of this application;

[0060] Figure 8 This is a schematic diagram of the structure of a signal transmission device provided in one embodiment of this application;

[0061] Figure 9 This is a schematic diagram of the structure of a signal transmission device provided in one embodiment of this application;

[0062] Figure 10 This is a top view of a signal transmission device provided in one embodiment of this application;

[0063] Figure 11 This is a schematic diagram of the structure of a signal transmission device provided in one embodiment of this application;

[0064] Figure 12 This is a schematic diagram of the structure of a signal transmission device provided in one embodiment of this application;

[0065] Figure 13 This is a top view of a signal transmission device provided in one embodiment of this application;

[0066] Figure 14 This is a schematic diagram of the structure of the first shielding cover in the signal transmission device provided in one embodiment of this application;

[0067] Figure 15 This is a schematic diagram of the structure of a signal transmission device provided in one embodiment of this application;

[0068] Figure 16 This is a bottom view of a signal transmission device provided in one embodiment of this application;

[0069] Figure 17 This is a schematic diagram of the structure of a signal transmission device provided in one embodiment of this application;

[0070] Figure 18 This is a top view of a signal transmission device provided in one embodiment of this application;

[0071] Figure 19 This is a schematic diagram of the structure of a signal transmission device provided in one embodiment of this application;

[0072] Figure 20 This is a schematic diagram of the structure of a signal transmission device provided in one embodiment of this application;

[0073] Figure 21 This is a bottom view of a signal transmission device provided in one embodiment of this application;

[0074] Figure 22 This is a top view of a signal transmission device provided in one embodiment of this application;

[0075] Figure 23 This is a schematic diagram of the structure of a signal transmission device provided in one embodiment of this application;

[0076] Figure 24 This is a schematic diagram of the structure of a signal transmission device provided in one embodiment of this application;

[0077] Figure 25 This is a schematic diagram of the structure of a signal transmission device provided in one embodiment of this application;

[0078] Figure 26This is a schematic diagram of the structure of a signal transmission device provided in one embodiment of this application;

[0079] Figure 27 This is a schematic diagram of the structure of a signal transmission device provided in one embodiment of this application;

[0080] Figure 28 This is a transmission performance distribution curve of the signal transmission device provided in one embodiment of this application for signal transmission;

[0081] Figure 29 This is a schematic diagram of the structure of a signal transmission device provided in one embodiment of this application;

[0082] Figure 30 This is a transmission performance distribution curve of the signal transmission device provided in one embodiment of this application for signal transmission;

[0083] Figure 31 This is a schematic diagram of the structure of a signal transmission device provided in one embodiment of this application;

[0084] Figure 32 This is a bottom view of a signal transmission device provided in one embodiment of this application;

[0085] Figure 33 This is a transmission performance distribution curve of the signal transmission device provided in one embodiment of this application for signal transmission;

[0086] Figure 34 This is a schematic diagram of the structure of a signal transmission device provided in one embodiment of this application;

[0087] Figure 35 This is a transmission performance distribution curve of the signal transmission device provided in one embodiment of this application for signal transmission;

[0088] Figure 36 This is a transmission performance distribution curve of a signal transmission device with vias provided in one embodiment of this application. Detailed Implementation

[0089] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0090] In this document, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0091] Furthermore, in this article, directional terms such as "upper" and "lower" are defined relative to the orientation of the structure as shown in the attached drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the structure.

[0092] For ease of understanding, the English abbreviations and related technical terms used in the embodiments of this application will be explained and described below.

[0093] Core layer and PP layer: The core layer includes a dielectric layer and metal sheets disposed on opposite surfaces of the dielectric layer, and is a solid structure; the PP layer is a dielectric layer, which is a semi-cured sheet before lamination, and the dielectric layer is an insulating dielectric layer.

[0094] Waveguide: A structure used to guide electromagnetic waves in a specific direction.

[0095] Bandwidth: The operating frequency range of a signal.

[0096] Blind holes are holes that connect the surface layer and the inner layer without penetrating the entire board.

[0097] Through hole: refers to a hole that runs through the entire board.

[0098] Impedance matching: When the internal resistance of the signal source is equal in magnitude and phase to the characteristic impedance of the connected transmission line, or when the characteristic impedance of the transmission line is equal in magnitude and phase to the impedance of the connected load, the input or output end of the transmission line is said to be in an impedance-matched state.

[0099] This application provides a signal transmission device and an electronic device. The signal transmission device can be a chip or PCB, etc., that requires vertical signal transmission. The chip and PCB can be used in electronic devices such as wireless communication, fixed-line communication, IT high-performance computing and interconnection, radio frequency terminals, drones, and automotive devices. For example, the electronic devices can be mobile phones, tablets, laptops, wearable products, and smart home terminal products. The signal transmission device includes a first signal layer, a second signal layer, and multiple connection layers located between the two. The first signal layer includes a first signal line and a first dielectric layer disposed adjacent to the connection layer. The second signal layer includes a second signal line and a second dielectric layer disposed adjacent to the connection layer. Signal transmission cavities are provided in the multiple connection layers. Signals are coupled and transmitted between the first signal line and the second signal line, which can realize high bandwidth and low insertion loss vertical signal transmission.

[0100] Please see Figure 1 , Figure 1This is a schematic diagram of the structure of an electronic device 20 provided in one embodiment. In this embodiment, the electronic device 20 is a mobile phone. The electronic device 20 includes a display screen 11, a mid-frame 12, and a back cover 13. A PCB 101, a chip 102, and other components are disposed between the mid-frame 12 and the back cover 13. The chip 102 is disposed on the PCB 101 and electrically connected to the PCB 101. In this embodiment, the PCB 101 and the chip 102 are disposed on the side of the mid-frame 12 facing the back cover 13. Other components include a camera device, a memory, an input device, a sensor, a power supply, and other mobile phone functional components. It should be noted that... Figure 1 The illustrated mobile phone structure does not constitute a limitation on the mobile phone and may include more or fewer components, or combine some components, or split some components, or have different component arrangements.

[0101] In one embodiment, PCB101 is the signal transmission device 10 described above. Please refer to [link to relevant documentation]. Figure 2 , Figure 2 This is a schematic diagram of PCB 101 and chip 102 mounted on PCB 101. Chip 102 includes a chip packaging substrate 21, a die 22, and a package shell 23. The chip packaging substrate 21 is located on one side of PCB 101, and the die 22 is located on the side of the chip packaging substrate 21 away from PCB 101. The package shell 23 covers the die 22 and the chip packaging substrate 21, and together with PCB 101, encapsulates the die 22 and the chip packaging substrate 21. One end of PCB 101 is electrically connected to the pins of chip 102, enabling signal transmission between chip 102 and PCB 101. The other end of PCB 101 can also be electrically connected to underlying devices, enabling PCB 101 to transmit signals between chip 102 and underlying devices. The die 22 can be configured as different functional devices or circuits according to actual needs.

[0102] In one embodiment, the chip packaging substrate 21 is the signal transmission device 10 described above. Please refer to [link to relevant documentation]. Figure 3 , Figure 3 This is a schematic diagram of the structure of a chip 102 without a package 23 provided in one embodiment. In this embodiment, a bare die 22 is disposed on one side of a chip package substrate 21. The chip package substrate 21 and the bare die 22 are electrically connected to realize signal transmission between the bare die 22 and external devices on the other side of the chip package substrate 21.

[0103] In some embodiments, the signal transmission device 10 may also be a flexible circuit board. The flexible circuit board has a flexible integrated circuit, which is electrically connected to the flexible circuit board to achieve vertical interconnection of signals within the flexible circuit board.

[0104] Please see Figures 4a to 5b ,in, Figure 4aThis is a top view of the signal transmission device 10 provided in one embodiment of this application. Figure 4b yes Figure 4a Sectional view along line AA, Figure 4c This is a top view of multiple connection layers 300 in a signal transmission device provided in one embodiment. Figure 4d yes Figure 4c Sectional view along line BB. Figure 5a This is a top view of a signal transmission device 10 provided in one embodiment, having a first signal line 110. Figure 5b This is a bottom view of a signal transmission device 10 provided in one embodiment. One embodiment of this application provides a signal transmission device 10, including a first signal layer 100, a second signal layer 200, and a plurality of connecting layers 300 located between the first signal layer 100 and the second signal layer 200. The first signal layer 100 includes a first signal line 110 and a first dielectric layer 120, with the first signal line 110 disposed away from the connecting layer 300 relative to the first dielectric layer 120. The second signal layer 200 includes a second signal line 210 and a second dielectric layer 220, with the second signal line 210 disposed away from the connecting layer 300 relative to the second dielectric layer 220. Signal transmission cavities 400 are provided in the plurality of connecting layers 300. Each signal transmission cavity 400 includes a first opening 410 and a second opening 420 disposed opposite to each other. The first opening 410 is disposed adjacent to the first dielectric layer 120, and the second opening 420 is disposed adjacent to the second dielectric layer 220. In this embodiment, through-holes 330 (e.g., ...) are formed in the plurality of connecting layers 300. Figure 4c and Figure 4d As shown, the through-hole 330, together with the first signal layer 100 and the second signal layer 200, forms a signal transmission cavity 400. The first opening 410 refers to the end of the through-hole 330 adjacent to the first dielectric layer 120, and the second opening 420 refers to the end of the through-hole 330 adjacent to the second dielectric layer 220. When the cross-section of the signal transmission cavity 400 is rectangular or circular, the areas of the first opening 410 and the second opening 420 are equal to the cross-sectional area of ​​the signal transmission cavity 400.

[0105] The orthographic projection of one end of the first signal line 110 onto the connection layer 300 at least partially overlaps with the orthographic projection of the first opening 410 onto the connection layer 300, and the orthographic projection of one end of the second signal line 210 onto the connection layer 300 at least partially overlaps with the orthographic projection of the second opening 320 onto the connection layer 300.

[0106] In this application, the first signal line 110 and the second signal line 210 are not on the same horizontal plane, but are vertically separated. The first signal line 110 is used to receive or transmit signals, and the second signal line 210 is used to receive or transmit signals. The signals can be millimeter waves or terahertz waves. The frequency range of millimeter waves is 30-300 GHz, and the frequency range of terahertz waves is 100-10000 GHz. In this embodiment, the first signal line 110 and the second signal line 210 are arranged in parallel. In some embodiments, the orthographic projections of the first signal line 110 and the second signal line 210 on the connection layer 300 can overlap, be parallel to each other, or be arranged at an angle. Please refer to [link to relevant documentation]. Figure 6a and Figure 6b , Figure 6a This is a schematic diagram of the orthographic projection of the first signal line 110 and the second signal line 210 on the connection layer 300 in a signal transmission device provided in an embodiment of this application. Figure 6b This is a schematic diagram of the orthographic projection of the first signal line 110 and the second signal line 210 onto the connection layer 300 in a signal transmission device 10 provided in one embodiment of this application; Figure 6a In the connection layer 300, the orthographic projections of the first signal line 110 and the second signal line 210 are set at an angle, which is an acute angle. In some embodiments, the angle may be an obtuse angle. Figure 6b In the middle, the orthographic projections of the first signal line 110 and the second signal line 210 on the connection layer 300 are set at right angles.

[0107] In one embodiment, one end of the first signal line 110 is a signal transmitting end 111 (e.g., Figure 4b As shown), one end of the second signal line 210 is the signal receiving end 211. For example, the signal transmission device 10 receives the chip 102 (such as...) through the first signal line 110. Figure 2 The signal (shown) is radiated from the signal transmitting end 111 of the first signal line 110 to the first opening 410, and then to the signal transmission cavity 400. It is then output from the second opening 420 and received by the signal receiving end 211 of the second signal line 210, and transmitted to the underlying device via the second signal line 210. In some embodiments, one end of the first signal line 110 is a signal receiving end, and one end of the second signal line 210 is a signal transmitting end. After receiving the signal via the second signal line 210, the signal transmission device 10 radiates it from the signal transmitting end of the second signal line 210 to the second opening 420, and then to the signal transmission cavity 400. It is then output from the first opening 410 and received by the signal receiving end of the first signal line 110, and transmitted via the first signal line 110. In the following embodiments, unless otherwise specified, the signal transmission process is illustrated using the first signal line 110 receiving the signal and the second signal line 210 transmitting the signal as examples.

[0108] In some embodiments, when the first signal line 110, the signal transmission cavity 400, and the second signal line 210 are parallel to each other, the first opening 410 and the second opening 420 are aligned in parallel, with one end of the first signal line 110 located above the first opening 410 and one end of the second signal line 210 located below the second opening 420.

[0109] The first signal line 110 can be attached to or coated on the surface of the first dielectric layer 120 away from the connecting layer 300. During fabrication, the first signal layer 100 is first pressed onto the surface of the connecting layer 300, and then the metal sheet of the first signal layer 100 away from the connecting layer 300 is patterned to form the first signal line 110. The fabrication method of the second signal layer 200 can be the same as that of the first signal layer 100. In this application, the dielectric layer is an insulating dielectric layer, such as the first dielectric layer 120 and the second dielectric layer 220, to avoid signal interference between layers.

[0110] The connection layer 300 can be a PP layer or a core layer. Multiple connection layers 300 include multiple PP layers and multiple core layers. The number of PP layers and core layers is not limited in this application and can be set according to actual needs. Figure 27 The connecting layer 300 shown consists of three core layers 310 and two PP layers 320 stacked alternately. The first dielectric layer 120 is a PP layer made of polypropylene; the second dielectric layer 220 is also a PP layer.

[0111] The signal transmission device 10 of this application transmits a signal from the first signal line 110 to one end of the first signal line 110, and then transmits the signal to the signal transmission cavity 400 by energy radiation at one end of the first signal line 110. The signal is then coupled to the second signal line 210 through the signal transmission cavity 400, and then transmitted to other electronic components from the second signal line 210. The signal transmission cavity 400 is not directly connected to the first signal line 110 and the second signal line 120, respectively. The signal is conducted by circuit on the first signal line 110 and the second signal line 210, and is transmitted between the first signal line 110 and the second signal line 210 by coupling. Compared with the via method, this transmission method has a lower insertion loss value and a higher bandwidth when transmitting millimeter wave and higher frequency band signals.

[0112] Specifically, when using vias to transmit signals, please refer to [link / reference needed]. Figure 7 , Figure 7This is a schematic diagram of a signal transmission device with a via 40 provided in one embodiment of this application. A first pad 41 is provided around one end of the via 40. The first signal line 110 is directly connected to the first pad 41. The first pad 41 is connected to the copper layer 43 on the inner wall of the via 40. The other end of the via 40 has a second pad 42, which is connected to the second signal line 210. The signal is transmitted from the first signal line 110, the first pad 41, the via 40, and the second pad 42 to the second signal line 210. In the millimeter-wave band, due to the parasitic effect of the circuit, the parasitic circuit of the signal via is very complex. For example, factors such as the size of the first pad 41, the size of the via 40, and the size of the second pad 42 all affect impedance matching. When the impedance matching is adjusted by adjusting the above factors, the signal transmission performance is sensitive to the above factors, so it is not easy to achieve impedance adjustment, the impedance matching is poor, and the transmission performance is seriously deteriorated.

[0113] When the coupling method of this application is used for transmission, when the signal emitted by the first signal line 110 is transmitted through the signal transmission cavity 400, the waveguide mode in a specific frequency band is excited by adjusting the cavity size, so that the signal transmission cavity 400 becomes a waveguide that can transmit signals in that specific frequency band; and the adjustment of the cavity size is not sensitive to the transmission performance, so the signal transmission device 10 of this application can have the advantages of high bandwidth and low insertion loss.

[0114] For example, when the signal is a millimeter wave with a frequency of 76 GHz, the shape and size of the signal transmission cavity 400 can be matched and set according to the characteristics of the millimeter wave. The cross-section of the signal transmission cavity 400 can be set as a rectangle, a circle, or a regular polygon. The more sides a regular polygon has, the closer it is to a circle, and the better the signal transmission effect. In this embodiment, it is set as a rectangle, so that the signal transmission cavity 400 becomes a rectangular waveguide. When the signal frequency is other frequencies, the structure and size of the signal transmission cavity 400 can be adjusted to adapt to the signal, so that the signal transmission cavity 400 becomes a waveguide structure adapted to the signal.

[0115] In addition, in this application, a first signal line 110 and a second signal line 210 are provided on both sides of the signal transmission cavity 400. The first signal line 110 is used to transmit signals output by other electronic components, and the signal is emitted from one end of the first signal line 110. After the signal completes the vertical transmission, the signal is received by the second signal line 210, and the second signal line 210 transmits the signal to other electronic components. In this application, signal lines are provided on both sides of the signal transmission cavity 400 for circuit signal transmission. The signal transmission cavity 400 is used for transmission in the vertical interconnection part, realizing signal transmission between the first signal line 110 on the surface of the signal transmission device 10 and the second signal line 210 on the bottom, which can reduce the vertical transmission loss of the signal.

[0116] When the signal transmission device 10 is a chip packaging substrate 21, the first signal line 110 may be disposed adjacent to the die 22 relative to the second signal line 210. In some embodiments, the second signal line 210 may be disposed adjacent to the die 22 relative to the first signal line 110.

[0117] Please see Figure 8 , Figure 8 This is a schematic diagram of the structure of a signal transmission device 10 according to one embodiment of this application. In this embodiment, a shielding layer 430 is provided on the inner wall of the signal transmission cavity 400, and the signal transmission cavity 400 is filled with a signal transmission medium 440. The shielding layer 430 is used to prevent signals propagating in the signal transmission cavity 400 from leaking out from the inner wall of the signal transmission cavity 400, thereby ensuring signal transmission efficiency. It can also shield external wireless signals from radiating into the signal transmission cavity 400 and interfering with the signal transmission in the signal transmission cavity 400. The material of the shielding layer 430 can be one of copper, aluminum, or iron, or other materials capable of shielding signals.

[0118] The signal transmission medium 440 can be selected according to the actual product. In some embodiments, the signal transmission medium 440 can be air, meaning that the signal is transmitted through air, which has an extremely low dielectric loss factor. In some embodiments, the signal transmission medium 440 can also be a semi-solid or solid transmission medium. The semi-solid transmission medium can be ink, etc. Other materials can be selected according to the characteristics of the signal and the transmission requirements. Furthermore, the parameters of the signal transmission medium 440 can be designed according to actual needs, with priority given to materials with lower dielectric loss factors, so that the signal transmission loss of the signal transmission cavity 400 is minimized. For a signal transmission cavity 400 where the signal transmission medium 440 is air, it is prone to deformation when the signal transmission device 10 is subjected to pressure. Furthermore, when the signal transmission cavity 400 is not filled with the signal transmission medium 440 or is not fully filled, the PP layer medium in the first medium layer 120 and the second medium layer 220 will flow unevenly during the pressing process between the first signal layer 100 and the second signal layer 200 and the signal transmission cavity 400, resulting in delamination and affecting the interlayer adhesion. However, a signal transmission cavity 400 filled with a semi-solid or solid transmission medium has stronger structural strength, is not easily deformed, and can avoid delamination problems.

[0119] Please see Figure 9 and Figure 10 , Figure 9 This is a schematic diagram of the structure of the signal transmission device 10 provided in one embodiment of this application. Figure 10This is a top view of a signal transmission device 10 provided in one embodiment. In this embodiment, a plurality of first shielding members 130 are further provided in the first signal layer 100. The plurality of first shielding members 130 are horizontally arranged around the signal transmission cavity 400 and the end of the first signal line 110 near the signal transmission cavity 400. "Horizontally arranged" means that the orthographic projection of the first shielding member 130 on the connecting layer 300 is arranged around the orthographic projection of the signal transmission cavity 400 and the end of the first signal line 110 near the signal transmission cavity 400 on the connecting layer 300. The first shielding members 130 are used to prevent the signal emitted by the first signal line 110 from radiating out of the plane where the first signal layer 100 is located, so that the signal emitted by the first signal line 110 can be radiated into the signal transmission cavity 400 with greater efficiency. The first shielding member 130 can be a metal sheet, a metal pillar, or a via. The metal can be one of copper, aluminum, or iron, or other materials capable of shielding signals. The via includes blind vias or through-holes. In this embodiment, the first shielding member 130 is a blind via 140. When the first shield 130 is a through hole, the first shield 130 needs to be set away from the second signal line 210 to avoid penetrating the second signal line 210.

[0120] In one possible implementation, the first shielding element 130 is arranged in a sheet shape, with one surface of the first shielding element 130 facing the signal transmission cavity 400 and the first signal line 110 to increase the signal shielding area. The number of first shielding elements 130 is not limited and can be set according to actual needs. The smaller the gap between two adjacent first shielding elements 130, the better the shielding effect. In one possible implementation, the gap between two adjacent first shielding elements 130 is less than 1 / 4 of the signal wavelength to reduce radiation loss.

[0121] In some embodiments, multiple first shielding members 130 may be arranged horizontally around the signal transmission cavity 400, that is, the orthographic projection of the first shielding member 130 on the connecting layer 300 is arranged around the orthographic projection of the signal transmission cavity 400 on the connecting layer 300. In some embodiments, there may be only one first shielding member 130, and this first shielding member 130 is arranged horizontally around the signal transmission cavity 400 and the end of the first signal line 110 near the signal transmission cavity 400. That is, in this embodiment, the first shielding member 130 is a single, seamless structural component.

[0122] In one possible implementation, the first signal layer 100 is further provided with a first conductive layer 150 (e.g., ...). Figure 9As shown, the first conductive layer 150 and the first signal line 110 are disposed on the same side of the first dielectric layer 120, and the first conductive layer 150 and the first signal line 110 are spaced apart. The first shielding member 130 penetrates through the first conductive layer 150 and the first dielectric layer 120. The first conductive layer 150 is grounded. The first conductive layer 150 and the first signal layer 100 can be simultaneously formed on the same side of the first dielectric layer 120. For example, a metal layer can be formed on one side of the first dielectric layer 120, and then the metal layer can be patterned to form the first signal line 110 and the first conductive layer 150. In some embodiments, the first shielding member 130 also penetrates to the connecting layer 300.

[0123] Please see Figure 11 , Figure 11 This is a schematic diagram of the structure of a signal transmission device 10 provided in one embodiment of this application. In this embodiment, a plurality of second shielding members 230 are provided in the second signal layer 200. The plurality of second shielding members 230 are horizontally arranged around the signal transmission cavity 400 and the end of the second signal line 210 near the signal transmission cavity 400. Specifically, the orthographic projection of the second shielding member 230 on the connecting layer 300 is arranged around the orthographic projection of the end of the second signal line 210 near the signal transmission cavity 400 on the connecting layer 300.

[0124] The second shielding element 230 is used to prevent the signal radiated from the signal transmission cavity 400 from radiating out of the second signal layer 200, so that the signal radiated from the signal transmission cavity 400 can be radiated to the second signal line 210 with greater efficiency and be received by the second signal line 210. The second shielding element 230 can be a metal sheet, a metal pillar, or a via. The metal can be one of copper, aluminum, or iron, or other materials capable of shielding signals. The via includes blind vias or through vias. In this embodiment, the second shielding element 230 is a blind via 240. When the second shielding element 230 is a through via, the second shielding element 230 must be positioned away from the first signal line 110 to avoid penetrating the first signal line 110.

[0125] In one possible implementation, the second shielding element 230 is arranged in a sheet-like form, with one surface of the second shielding element 230 facing the signal transmission cavity 400 and the second signal line 210 to increase the signal shielding area. The number of second shielding elements 230 is not limited and can be set according to actual needs. The smaller the gap between two adjacent second shielding elements 230, the better the shielding effect. In one possible implementation, the gap between two adjacent second shielding elements 230 is less than 1 / 4 of the signal wavelength to reduce radiation loss.

[0126] In some embodiments, multiple second shielding members 230 may be arranged horizontally around the signal transmission cavity 400, that is, the orthographic projection of the second shielding member 230 on the connecting layer 300 is arranged around the orthographic projection of the signal transmission cavity 400 on the connecting layer 300. In some embodiments, there may be a single second shielding member 230, and this second shielding member 230 is arranged horizontally around the signal transmission cavity 400 and the end of the second signal line 210 near the signal transmission cavity 400. That is, in this embodiment, the second shielding member 230 is a single, seamless structural component.

[0127] In one possible implementation, the second signal layer 200 further includes a second conductive layer 250, which is disposed on the same side of the second dielectric layer 220 as the second signal line 210, and the second conductive layer 250 and the second signal line 210 are spaced apart. A second shielding member 230 penetrates through the second conductive layer 250 and the second dielectric layer 220. The second conductive layer 250 is grounded. The second conductive layer 250 and the second signal line 210 can be simultaneously formed on the same side of the second dielectric layer 220. For example, a metal layer can be formed on one side of the second dielectric layer 220, and then the metal layer can be patterned to form the second signal line 210 and the second conductive layer 250. In some embodiments, the second shielding member 230 also extends to the connecting layer 300.

[0128] Please see Figure 12 and Figure 13 , Figure 12 This is a schematic diagram of the structure of the signal transmission device 10 provided in one embodiment of this application. Figure 13 This is a top view of a signal transmission device 10 provided in one embodiment of this application. In this embodiment, the signal transmission device 10 further includes a first shielding cover 160. The first shielding cover 160 is disposed on the side of the first signal line 110 away from the signal transmission cavity 400 and is insulated from the first signal line 110. The orthographic projection of the first shielding cover 160 on the connecting layer 300 at least covers the first opening 410 of the signal transmission cavity 400. The first shielding cover 160 prevents the signal emitted by the first signal line 110 from radiating out from the side of the first signal line 110 away from the signal transmission cavity 400, thereby reducing loss. It also prevents external wireless signals from entering the signal transmission cavity 400 and interfering with signal transmission within the signal transmission cavity 400. Please refer to [link to relevant documentation]. Figure 14 , Figure 14This is a schematic diagram of the structure of a first shielding cover 160 provided in one embodiment. The first shielding cover 160 includes a top wall 161 and a peripheral wall 162. A notch 163 is provided in the peripheral wall 162, through which the first signal line 110 passes to prevent the first signal line 110 from being electrically connected to the first shielding cover 160. In some embodiments, an insulating layer is provided between the first shielding cover 160 and the first signal line 110 to insulate them from each other. The first shielding cover 160 may be a copper layer.

[0129] Please see Figure 15 and Figure 16 , Figure 15 This is a schematic diagram of the structure of the signal transmission device 10 provided in one embodiment of this application. Figure 16 This is a top view of a signal transmission device 10 provided in one embodiment of this application. In this embodiment, the signal transmission device 10 further includes a second shielding cover 260. The second shielding cover 260 is disposed on the side of the second signal line 210 away from the signal transmission cavity 400 and is insulated from the second signal line 210. The orthographic projection of the second shielding cover 260 on the connecting layer 300 at least covers the second opening 420 of the signal transmission cavity 400. The second shielding cover 260 can prevent signals radiated from the signal transmission cavity 400 from radiating out from the side of the second signal line 210 away from the signal transmission cavity 400, so that the signal can be effectively radiated to the second signal line 210, improving signal coupling efficiency and reducing signal loss. On the other hand, it can prevent external wireless signals from entering the signal transmission cavity 400 and interfering with the signal transmission in the signal transmission cavity 400. The second shielding cover 260 can also be electrically connected to the second signal line 210 by having a notch in its peripheral wall and passing the second signal line 210 through the notch. In some embodiments, the second shield 260 and the second signal line 210 are insulated from each other by providing an insulating layer.

[0130] Please see Figure 17 and Figure 18 , Figure 17 This is a schematic diagram of the structure of the signal transmission device 10 provided in one embodiment of this application. Figure 18This is a top view of a signal transmission device 10 provided in one embodiment of this application. In this embodiment, the signal transmission device 10 further includes a first signal array 170, which is connected to one end of a first signal line 110, and its orthographic projection on the signal transmission cavity 400 is located within the signal transmission cavity 400. The first signal array 170 is used to increase the area of ​​the first signal line 110 for transmitting or receiving signals, thereby improving the signal transmission efficiency between the first signal line 110 and the second signal line 210. In this embodiment, the first signal array 170 is a copper layer. In some embodiments, the material of the first signal array 170 can also be aluminum or iron. The shape and specific size of the first signal array 170 can be set according to the signal transmission efficiency and actual product requirements, and are not limited in this application.

[0131] In some embodiments, the first signal element 170 may be printed together with the first signal line 110, or a copper sheet may be attached as the first signal element 170 to one end of the first signal line 110 adjacent to the signal transmission cavity 400.

[0132] Please see Figure 19 , Figure 19 This is a schematic diagram of the structure of a signal transmission device 10 according to one embodiment of this application. In this embodiment, the signal transmission device 10 further includes a first signal element 170, which is located between the first signal line 110 and the second signal line 210, and its orthographic projection on the signal transmission cavity 400 is located within the signal transmission cavity 400. In some embodiments, the first signal element 170 is located on the surface of the first dielectric layer 120 away from the first signal line 110, and the first signal element 170 is disposed adjacent to the first opening 210 to improve the signal transmission efficiency between the first signal line 110 and the second signal line 210. In other embodiments, the first signal element 170 can be located at any position between the first signal line 110 and the second signal line 210, and can be located within the cavity of the signal transmission cavity 400. When located within the cavity of the signal transmission cavity 400, the signal transmission medium 440 of the signal transmission cavity 400 is semi-solid or solid, so that the first signal element 170 is fixed in the signal transmission medium 440. In other embodiments, the first signal element 170 is located on the surface of the second dielectric layer 220 away from the second signal line 210, in order to improve the transmission efficiency of the signal between the first signal line 110 and the second signal line 210.

[0133] In one possible implementation, the first signal layer 100 further includes a third conductive layer 180 and a third dielectric layer 190. The third conductive layer 180 is disposed on the side of the first dielectric layer 120 away from the first signal line 110, and the third dielectric layer 190 is disposed between the plurality of connection layers 300 and the third conductive layer 180. The orthographic projection of the third conductive layer 180 on the connection layer 300 does not overlap with the orthographic projection of the signal transmission cavity 400 on the connection layer 300. In this embodiment, the first signal layer 100 includes a core layer and a PP layer. The core layer is disposed away from the connection layer 300 relative to the PP layer. The first signal line 110 and the first conductive layer 150 are patterned metal sheets on one surface of the core layer, and the third conductive layer 180 and the first signal element 170 are patterned metal sheets on the other surface of the core layer. The PP layer is the third dielectric layer 190. In some embodiments, the second signal layer 200 includes a core layer and a PP layer.

[0134] In one possible implementation, the first signal element 170 may be disposed on the side of the first dielectric layer 120 away from the interconnect layer 300, or it may be disposed between the first dielectric layer 120 and the third dielectric layer 190. In this embodiment, the first signal element 170 is disposed between the first dielectric layer 120 and the third dielectric layer 190 (e.g., Figure 19 As shown, the first signal element 170 and the third conductive layer 180 are spaced apart, and their orthogonal projections on the signal transmission cavity 400 are located inside the signal transmission cavity 400.

[0135] Please see Figure 20 and Figure 21 , Figure 20 This is a schematic diagram of the structure of the signal transmission device 10 provided in one embodiment of this application. Figure 21 This is a bottom view of a signal transmission device 10 according to one embodiment of this application. In this embodiment, the signal transmission device 10 further includes a second signal array 270, which is connected to one end of the second signal line 210, and its orthographic projection on the signal transmission cavity 400 is located within the signal transmission cavity 400. The second signal array 270 is used to increase the area of ​​the second signal line 210 for transmitting or receiving signals, thereby improving the signal transmission efficiency between the first signal line 110 and the second signal line 210. In some embodiments, the signal transmission device 10 simultaneously includes a first signal array 170 and a second signal array 270, respectively increasing the signal transmission area of ​​the first signal line 110 and the second signal line 210, thereby improving the signal transmission efficiency between the first signal line 110 and the second signal line 210 and reducing losses.

[0136] Please see Figure 22 , Figure 22This is a top view of a signal transmission device 10 provided in one embodiment of this application. In this embodiment, the signal transmission device 10 is further provided with a grounding hole 500 penetrating the first signal layer 100, the second signal layer 200, and a plurality of connection layers 200. The grounding hole 500 is horizontally arranged around the side of the first shield 130 away from the signal transmission cavity 400, the first signal line 110, and the second signal line 210. The number of grounding holes is not limited and can be set according to actual needs.

[0137] Please see Figure 23 , Figure 23 This is a schematic diagram of the structure of a signal transmission device 10 provided in one embodiment of this application. In this embodiment, at least one first connecting sublayer 340 is further provided between the first signal layer 100 and the connecting layer 300. The first connecting sublayer 340 can be a core layer or a PP layer. When the first connecting sublayer 340 is a PP layer, it can cover the first opening 410 of the signal transmission cavity 400. When the first connecting sublayer 340 is a core layer, the orthographic projection of the metal sheet in the core layer onto the connecting layer 300 does not overlap with the orthographic projection of the first opening 410 onto the connecting layer 300, so as to avoid the signal radiated from the first signal line 110 being shielded by the metal sheet in the first connecting sublayer 340 and thus unable to radiate into the signal transmission cavity 400. In some embodiments, the multiple first connecting sublayers 340 include multiple core layers and multiple PP layers arranged in an alternating manner.

[0138] In some embodiments, at least one second connecting sublayer 350 is further provided between the second signal layer 200 and the connecting layer 300. The second connecting sublayer 350 can be a core layer or a PP layer. When the second connecting sublayer 350 is a PP layer, it can cover the second opening 420 of the signal transmission cavity 400. When the second connecting sublayer 350 is a core layer, the orthographic projection of the metal sheet in the core layer onto the connecting layer 300 does not overlap with the orthographic projection of the second opening 420 onto the connecting layer 300, so as to prevent the signal radiated from the signal transmission cavity 400 from being shielded by the metal sheet in the second connecting sublayer 350 and thus unable to radiate onto the second signal line 210. In some embodiments, the plurality of second connecting sublayers 350 include multiple core layers and multiple PP layers arranged in an alternating manner.

[0139] Please see Figure 24 , Figure 24This is a schematic diagram of the structure of a signal transmission device 10 provided in one embodiment of this application. In this embodiment, at least one first cover layer 600 is provided on the side of the first signal layer 100 away from the connection layer 300. The first cover layer 600 can be a core layer or a PP layer. In some embodiments, other electronic devices or functional circuits can also be disposed on the surface of the first cover layer 600 away from the first signal layer 100, but electronic devices or functional circuits that will not affect the signal transmission between the first signal line 110 and the second signal line 210 are preferred.

[0140] In some embodiments, at least one second cover layer 700 is provided on the side of the second signal layer 200 away from the connection layer 300. The second cover layer 700 can be a core layer or a PP layer. In some embodiments, other electronic devices or functional circuits can also be disposed on the surface of the second cover layer 700 away from the second signal layer 200, but electronic devices or functional circuits that will not affect the signal transmission between the first signal line 110 and the second signal line 210 are preferred.

[0141] Please see Figure 25 , Figure 25 This is a schematic diagram of the structure of a signal transmission device 10 according to one embodiment of this application. In this embodiment, the signal transmission device 10 further includes a first signal element 170, which is disposed at one end of a first signal line 110. A first cover layer 600 is located on the surfaces of the first signal line 110 and the first signal element 170 away from the connecting layer 300. In some embodiments, the signal transmission device 10 further includes a second signal element 270, which is disposed at one end of a second signal line 210. A second cover layer 700 is located on the surfaces of the second signal line 210 and the second signal element 270 away from the connecting layer 300.

[0142] Please see Figure 26 , Figure 26 This is a schematic diagram of the structure of a signal transmission device 10 according to one embodiment of this application. In this embodiment, the signal transmission device 10 further includes a first shielding cover 160, and a first covering layer 600 is located on the side of the first signal layer 100 away from the connecting layer 300 and covers the first shielding cover 160. In some embodiments, the signal transmission device 10 further includes a second shielding cover 260, and a second covering layer 700 is located on the side of the second signal layer 200 away from the connecting layer 300 and covers the second shielding cover 260.

[0143] To illustrate the beneficial effects of the signal transmission device 10 in this application, the following comparative description of the embodiments and comparative embodiments is also provided.

[0144] Implementation Method 1

[0145] Please see Figure 27 As shown, Figure 27 This is a schematic diagram of the signal transmission device 10a provided in Embodiment 1. The signal transmission device 10a includes a first signal layer 100, a second signal layer 200, and a plurality of connecting layers 300 located between the first signal layer 100 and the second signal layer 200. The first signal layer 100 includes a first signal line 110, a first conductive layer 150, and a first dielectric layer 120. The first signal line 110 and the first conductive layer 150 are disposed further away from the connecting layer 300 than the first dielectric layer 120, and are spaced apart and insulated from each other. The second signal layer 200 includes a second signal line 210, a second conductive layer 250, and a second dielectric layer 220. The second signal line 210 and the second conductive layer 250 are disposed further away from the connecting layer 300 than the second dielectric layer 220, and are spaced apart and insulated from each other. The first dielectric layer 120 and the second dielectric layer 220 are PP layers.

[0146] A signal transmission cavity 400 is provided in multiple connection layers 300. The signal transmission cavity 400 includes a first opening 410 and a second opening 420 disposed opposite to each other. The first opening 410 is disposed adjacent to the first dielectric layer 120, and the second opening 420 is disposed adjacent to the second dielectric layer 220. One end of the first signal line 110 has a first signal element 170. The orthographic projection of one end of the first signal line 110 on the connection layer 200 at least partially overlaps with the orthographic projection of the first opening 410 on the connection layer 200. The orthographic projection of the first signal element 170 on the signal transmission cavity 400 is located within the signal transmission cavity 400. One end of the second signal line 210 has a second signal element 270. The orthographic projection of one end of the second signal line 210 on the connection layer 200 at least partially overlaps with the orthographic projection of the second opening 320 on the connection layer 200. The orthographic projection of the second signal element 270 on the signal transmission cavity 400 is located within the signal transmission cavity 400.

[0147] The multiple connection layers 300 include three core layers 310 and two PP layers 320, which are staggered and stacked. A signal transmission cavity 400 is formed in the multiple connection layers 300, and a copper layer is electroplated on the inner wall of the signal transmission cavity 400 as a shielding layer 430. The signal transmission cavity 400 is rectangular, and its size is set according to the frequency band of the signal to be transmitted. In this embodiment, the transmitted signal is a millimeter wave with a frequency band of 76-81 GHz, and the size of the signal transmission cavity 400 matching this frequency band can be obtained in advance through simulation.

[0148] After the signal transmission cavity 400 is formed, the first signal layer 100 and the second signal layer 200 are pressed onto the upper and lower surfaces of the plurality of connecting layers 300. A plurality of blind holes are formed on the first signal layer 100 and the second signal layer 200, respectively. These blind holes serve as the first shield 130 of the first signal layer 100 and the second shield 230 of the second signal layer 200. The first shield 130 is horizontally arranged around the signal transmission cavity 400 and the end of the first signal line 110 near the signal transmission cavity 400, and the second shield 230 is horizontally arranged around the signal transmission cavity 400 and the end of the second signal line 210 near the signal transmission cavity 400. The signal transmission device 10a also includes a grounding hole penetrating the signal transmission device 10a.

[0149] When millimeter waves in the 76-81 GHz frequency band pass through this embodiment, the distribution curves of insertion loss A1, first return loss A2, and second return loss A3 are obtained through simulation. The first return loss refers to the return loss of the signal from the first signal line 110 to the second signal line 210, and the second return loss refers to the return loss from the second signal line 210 to the first signal line 110. For details, please refer to [link to relevant documentation]. Figure 28 ,from Figure 28 It can be seen that, when using the signal transmission device 10a of the above embodiment 1, the maximum insertion loss is 2.42dB, the maximum first return loss is -15.38dB, and the maximum second return loss is -15.39dB when the transmission frequency band is 76-81GHz millimeter wave. It should be noted that the insertion loss is expressed in absolute value, and its actual value is negative. The larger the insertion loss value is, the closer it is to zero. The smaller the first return loss and the second return loss values ​​are, the better the signal transmission efficiency.

[0150] Implementation Method 2

[0151] Please see Figure 29 , Figure 29 This is a schematic diagram of the signal transmission device 10b provided in Embodiment 2. Unlike Embodiment 1, the first signal layer 100 in the signal transmission device 10b includes a core layer and a PP layer, where the PP layer is a dielectric layer. Specifically, a third conductive layer 180 and a first signal element 170 are provided on the surface of the first dielectric layer 120 away from the first signal line 110 and the first conductive layer 150. The third conductive layer 180 and the first signal element 170 are spaced apart and insulated. The orthographic projection of the first signal element 170 in the signal transmission cavity 400 is located inside the signal transmission cavity 400. A third dielectric layer 190 is provided on the side of the third conductive layer 180 and the first signal element 170 away from the first dielectric layer 120. The first shield 130 penetrates the first signal layer 100.

[0152] When millimeter waves in the 76-81 GHz frequency band pass through this embodiment, the distribution curves of the signal insertion loss A1, first return loss A2, and second return loss A3 are obtained through simulation. For details, please refer to [link to relevant documentation]. Figure 30 ,from Figure 30 It can be seen that, when using the signal transmission device 10d of the above embodiment 2, the maximum insertion loss is 1.28dB, the maximum first return loss is -16.30dB, and the maximum second return loss is -11.76dB when the transmission frequency band is 76-81GHz millimeter wave.

[0153] Implementation Method 3

[0154] Please see Figure 31 and Figure 32 , Figure 31 This is a schematic diagram of the signal transmission device 10c provided in Embodiment 3. Figure 32 This is a bottom view of the signal transmission device 10c. Unlike embodiment 1, the signal transmission device 10c further includes a first shielding cover 160 and a second shielding cover 260. The first shielding cover 160 is disposed on the side of the first signal line 110 away from the connecting layer 300 and is insulated from the first signal line 110. The orthographic projection of the first shielding cover 160 on the connecting layer 300 covers the first opening 410 of the signal transmission cavity 400. The second shielding cover 260 is disposed on the side of the second signal line 210 away from the connecting layer 300 and is insulated from the second signal line 210. The orthographic projection of the second shielding cover 260 on the connecting layer 300 covers the second opening 420 of the signal transmission cavity 400.

[0155] When millimeter waves in the 76-81 GHz frequency band pass through this embodiment, the distribution curves of the signal insertion loss A1, first return loss A2, and second return loss A3 are obtained through simulation. For details, please refer to [link to relevant documentation]. Figure 33 ,from Figure 33 It can be seen that, when using the signal transmission device 10c of the above embodiment 3, the maximum insertion loss is 0.55dB, the maximum first return loss is -16.39dB, and the maximum second return loss is -16.35dB when the transmission frequency band is 76-81GHz millimeter wave.

[0156] Implementation Method 4

[0157] Please see Figure 34 , Figure 34This is a schematic diagram of the signal transmission device 10d provided in Embodiment 4. Unlike Embodiment 3, the first signal layer 100 in the signal transmission device 10d includes a core layer and a PP layer, where the PP layer is a dielectric layer. Specifically, a third conductive layer 180 and a first signal element 170 are provided on the surface of the first dielectric layer 120 away from the first signal line 110 and the first conductive layer 150. The third conductive layer 180 and the first signal element 170 are spaced apart and insulated. The orthographic projection of the first signal element 170 in the signal transmission cavity 400 is located inside the signal transmission cavity 400. A third dielectric layer 190 is provided on the side of the third conductive layer 180 and the first signal element 170 away from the first dielectric layer 120. The first shield 130 penetrates the first signal layer 100.

[0158] When millimeter waves in the 76-81 GHz frequency band pass through this embodiment, the distribution curves of the signal insertion loss A1, first return loss A2, and second return loss A3 are obtained through simulation. For details, please refer to [link to relevant documentation]. Figure 35 ,from Figure 35 It can be seen that, when using the signal transmission device 10d of the above embodiment 4, the maximum insertion loss is 0.81dB, the maximum first return loss is -11.92dB, and the maximum second return loss is -12.99dB when the transmission frequency band is 76-81GHz millimeter wave.

[0159] Comparative implementation methods

[0160] Unlike embodiments 1-4, the comparative embodiment uses a conventional via method for vertical signal transmission, and the structure of this signal transmission device is as follows: Figure 7 As shown, the device includes a first signal line 110, a second signal line 210, and multiple connection layers 300 between the first signal line 110 and the second signal line 210. The multiple connection layers 300 include multiple core layers and PP layers arranged in an alternating manner. The signal transmission device includes a through-hole 40. A first pad 41 is provided around one end of the through-hole 40 adjacent to the first signal line 110. The first signal line 110 is directly connected to the first pad 41. The first pad 41 is connected to the copper layer 43 on the inner wall of the through-hole 40. A second pad 42 is provided around one end of the through-hole 40 adjacent to the second signal line 210. The second pad 42 is connected to the second signal line 210. The signal is transmitted from the first signal line 110, the first pad 41, the through-hole 40, and the second pad 42 to the second signal line 210.

[0161] When millimeter waves in the 76-81 GHz frequency band pass through this comparative embodiment, the insertion loss performance A1, the first return loss A2, and the second return loss A3 are obtained through simulation. For details, please refer to [link to relevant documentation]. Figure 36 ,from Figure 36It can be seen that, when using the signal transmission device of the above comparative implementation method, the maximum insertion loss is 7.56dB, the maximum first return loss is -4.90dB, and the maximum second return loss is greater than -8.33dB when the transmission frequency band is 76-81GHz millimeter wave.

[0162] The maximum insertion loss, maximum first return loss, and maximum second return loss of the above embodiments 1-4 and the comparative embodiments are compared as shown in Table 1.

[0163] Table 1

[0164] Vertical connection type Maximum insertion loss Maximum first return loss Maximum second return loss Comparative implementation methods 7.56dB -4.90dB -8.33dB

[0165] Implementation Method 1 2.42dB -15.38dB -15.39dB Implementation Method 2 1.3dB -16.30dB -11.76dB Implementation Method 3 0.55dB -16.39dB -16.35dB Implementation Method 4 0.81dB -11.92dB -12.99dB

[0166] As can be seen from Table 1, the maximum insertion loss values ​​of Embodiments 1 to 4 of this application are smaller than the maximum insertion loss values ​​of the comparative embodiments, that is, closer to zero. Furthermore, the maximum first return loss of Embodiments 1 to 4 is smaller than the maximum first return loss of the comparative embodiments, and the maximum second return loss of Embodiments 1 to 4 is smaller than the maximum second return loss of the comparative embodiments. Overall, the transmission performance of Embodiments 1-4 of this application is better than that of the comparative embodiments when transmitting signals.

[0167] 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 scope of the technology 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 signal transmission device, characterized in that, The signal transmission device includes a first signal layer, a second signal layer, and a plurality of connection layers located between the first signal layer and the second signal layer. The first signal layer includes a core layer and a PP layer, with the PP layer distributed between the core layer and the connection layers. The core layer includes a first dielectric layer and two metal sheets distributed on opposite surfaces of the first dielectric layer. One metal sheet of the core layer away from the connection layer includes a first signal line, and the other metal sheet of the core layer near the connection layer includes a third conductive layer and a first signal element. The second signal layer includes a second signal line and a second dielectric layer, with the second signal line disposed away from the connection layer relative to the second dielectric layer. The plurality of connection layers are provided with signal transmission cavities, each including a first opening and a second opening disposed opposite to each other. The first opening is disposed adjacent to the PP layer, and the second opening is disposed adjacent to the second dielectric layer. The orthographic projection of one end of the first signal line on the connection layer at least partially overlaps with the orthographic projection of the first opening on the connection layer; the orthographic projection of the third conductive layer on the connection layer does not overlap with the orthographic projection of the signal transmission cavity on the connection layer; the orthographic projection of the first signal element on the signal transmission cavity is located inside the signal transmission cavity; and the orthographic projection of one end of the second signal line on the connection layer at least partially overlaps with the orthographic projection of the second opening on the connection layer.

2. The signal transmission device according to claim 1, characterized in that, The inner wall of the signal transmission cavity is provided with a shielding layer, and the signal transmission cavity is filled with a signal transmission medium.

3. The signal transmission device according to claim 1, characterized in that, The signal transmission device further includes a first shield, which is disposed on the side of the first signal line away from the signal transmission cavity and is insulated from the first signal line. The orthographic projection of the first shield on the connection layer at least covers the first opening of the signal transmission cavity.

4. The signal transmission device according to claim 1, characterized in that, The signal transmission device further includes a second shield, which is disposed on the side of the second signal line away from the signal transmission cavity and is insulated from the second signal line. The orthographic projection of the second shield on the connection layer at least covers the second opening of the signal transmission cavity.

5. The signal transmission device according to claim 1, characterized in that, The signal transmission device further includes a second signal element, which is connected to one end of the second signal line, and its orthographic projection on the signal transmission cavity is located inside the signal transmission cavity.

6. The signal transmission device according to claim 1, characterized in that, The first signal layer is further provided with a plurality of first shielding components, which are arranged horizontally around the signal transmission cavity and the end of the first signal line near the signal transmission cavity.

7. The signal transmission device according to claim 6, characterized in that, The first shielding component is a metal sheet, a metal pillar, or a via.

8. The signal transmission device according to claim 7, characterized in that, The first signal layer is further provided with a first conductive layer. The first conductive layer and the first signal line are disposed on the same side of the first dielectric layer, and the first conductive layer and the first signal line are spaced apart. The first shielding member penetrates through the first conductive layer and the first dielectric layer.

9. The signal transmission device according to claim 1, characterized in that, The second signal layer is provided with a plurality of second shielding components, which are arranged horizontally around the signal transmission cavity and the end of the second signal line near the signal transmission cavity.

10. The signal transmission device according to claim 7, characterized in that, The signal transmission device is also provided with a grounding hole that penetrates the first signal layer, the second signal layer and the plurality of connection layers; the grounding hole is horizontally arranged around the side of the first shield that is away from the signal transmission cavity, the first signal line and the second signal line.

11. The signal transmission device according to any one of claims 1-10, characterized in that, The signal transmission device is a circuit board.

12. The signal transmission device according to any one of claims 1-10, characterized in that, The signal transmission device is a chip packaging substrate.

13. An electronic device, characterized in that, The electronic device includes a mid-frame, a back cover, a chip located between the mid-frame and the back cover, and a signal transmission device as described in claim 11, wherein the chip is disposed on the signal transmission device and electrically connected to the signal transmission device.

14. An electronic device, characterized in that, The electronic device includes a mid-frame, a back cover, and a circuit board and a chip located between the mid-frame and the back cover. The chip is disposed on the circuit board and includes a die and a signal transmission device as described in claim 12. The die is disposed on one side of the signal transmission device and is electrically connected to the signal transmission device.

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