阅读说明：本技术 信号传输结构及电路结构 (Signal transmission structure and circuit structure ) 是由 雷江 于 2021-08-17 设计创作，主要内容包括：本申请公开了一种信号传输结构及电路结构,该信号传输结构用于传输电路中的高速信号,其包括信号传输部、绝缘部和信号回流部,所述信号传输部用于传输驱动信号,所述绝缘部包覆于所述信号传输部的外表面,所述信号回流部设置于所述绝缘部的外表面,用于传输回流信号,且所述信号回流部的信号传输方向与所述信号传输部的信号传输方向平行且相反。本申请在传输高速信号时,使驱动信号能够经信号传输部在两电路层间流通,使回流信号能够经信号回流部尽快回流到信号的下方,避免了高速信号换层传输带来的阻抗突变问题,且无需开设地孔,减少了基板面积的占用,降低了生产成本。(The application discloses signal transmission structure and circuit structure, this signal transmission structure are arranged in the high-speed signal of transmission circuit, and it includes signal transmission portion, insulating part and signal backward flow portion, signal transmission portion is used for transmitting drive signal, the insulating part cladding in the surface of signal transmission portion, signal backward flow portion set up in the surface of insulating part for transmit backward flow signal, just the signal transmission direction of signal backward flow portion with the signal transmission direction of signal transmission portion is parallel and opposite. This application makes drive signal can circulate between two circuit layers through signal transmission portion when transmitting high-speed signal, makes the backward flow signal can flow back the below of signal as early as possible through signal backward flow portion, has avoided the impedance sudden change problem that high-speed signal trades the transmission and brings, and need not to set up the ground hole, has reduced the occupation of base plate area, has reduced manufacturing cost.)

1. A signal transmission structure is used for transmitting high-speed signals in a circuit; it is characterized by comprising:

a signal transmission section for transmitting a driving signal;

an insulating part covering the outer surface of the signal transmission part;

the signal backflow part is arranged on the outer surface of the insulating part and used for transmitting backflow signals, and the signal transmission direction of the signal backflow part is opposite to that of the signal transmission part.

2. The signal transmission structure according to claim 1, wherein the signal return portion has a cross section of a ring-shaped structure, and the signal return portion is sleeved outside the insulating portion.

3. The signal transmission structure according to claim 1, wherein the insulating portion is made of a printed circuit board medium.

4. The signal transmission structure according to claim 1, wherein the signal transmission section is made of metal or according to a printed circuit board circuit process.

5. The signal transmission structure according to claim 1, wherein the signal reflow portion is made of metal or according to a printed circuit board circuit process.

6. The signal transmission structure according to any one of claims 1 to 5, wherein the insulator is connected to an outer surface of the signal transmission section by bonding, and the signal return section is connected to an outer surface of the insulator by bonding.

7. A circuit structure, comprising a substrate and the signal transmission structure as claimed in any one of claims 1 to 5, wherein the substrate is provided with a via hole and at least two circuit layers, the signal transmission structure is disposed in the via hole, and the length extension direction of the signal transmission structure is the same as the length extension direction of the via hole, and the circuit layers for transmitting high-speed signals are electrically connected through the signal transmission structure.

8. The circuit structure of claim 7, wherein the size and shape of the cross section of the signal transmission structure are arranged corresponding to the size and shape of the via hole.

9. The circuit structure of claim 8, wherein an outer surface of the signal return is adhesively connected to the via wall.

10. The circuit structure of claim 7, wherein two of the at least two circuit layers are used for transmitting high-speed signals, the two circuit layers for transmitting the high-speed signals are electrically connected through the signal transmission structure, and the length of the signal transmission structure is the same as the distance between the two circuit layers for transmitting the high-speed signals.

Technical Field

The present disclosure relates to the field of high-speed signal transmission technology in a circuit, and more particularly, to a signal transmission structure for transmitting a high-speed signal in a circuit and a circuit structure having the same.

Background

After the chip (integrated circuit) is produced, the corresponding pins need to be led out to the printed circuit board, and the printed circuit board is connected to other chips, interfaces or passive devices, etc. to be made into modules, systems or products, so as to be applied.

As the functions of modules, systems or products become more and more powerful, the structure of a circuit board (a chip substrate or a printed circuit board) becomes more and more complex, a plurality of circuit layers are usually disposed in the circuit board along the thickness direction of the circuit board, and in order to achieve electrical connection between the circuit layers, a metal through hole is usually disposed on the circuit board, and the circuit layers to be electrically connected can be electrically connected through the metal through hole.

When the electric signal is transmitted in the circuit board, the flow direction of the signal starts from the driver, and flows to the load along the routing on the circuit board; and then, the signal returns to the driving end from the load end along the ground plane through the shortest path or the path with the minimum impedance, and for a high-speed signal, the shortest path (with the minimum impedance) is often the reference ground right below the transmission line, so that in order to return the return path to the lower part of the signal as soon as possible, in the prior art, a ground hole is usually added near the signal layer change, and the addition of the ground hole causes the area occupied by the circuit board to be larger, and the generation cost is high.

Disclosure of Invention

In order to overcome the problems in the prior art, the present application mainly aims to provide a signal transmission structure that occupies a small area of a substrate and has a low production cost.

In order to achieve the above purpose, the following technical solutions are specifically adopted in the present application:

the present application provides a signal transmission structure for transmitting a high-speed signal in a circuit, the signal transmission structure including:

a signal transmission section for transmitting a driving signal;

an insulating part covering the outer surface of the signal transmission part;

the signal backflow part is arranged on the outer surface of the insulating part and used for transmitting backflow signals, and the signal transmission direction of the signal backflow part is opposite to that of the signal transmission part.

In a specific embodiment, the cross section of the signal return part is in a ring structure, and the signal return part is sleeved outside the insulating part.

In a specific embodiment, the insulating portion is made of a printed circuit board medium.

In a specific embodiment, the signal transmission part is made of metal or made according to a printed circuit board circuit process.

In a specific embodiment, the signal return portion is made of metal or made according to a printed circuit board circuit process.

In a specific embodiment, the insulator is adhesively attached to an outer surface of the signal transmission portion, and the signal return portion is adhesively attached to an outer surface of the insulator.

Correspondingly, the application also provides a circuit structure, which comprises a substrate and the signal transmission structure, wherein the substrate is provided with a via hole and at least two circuit layers, the signal transmission structure is arranged in the via hole, the length extending direction of the signal transmission structure is the same as that of the via hole, and the circuit layers for transmitting high-speed signals are electrically connected through the signal transmission structure.

In a specific embodiment, the size and the shape of the cross section of the signal transmission structure correspond to the size and the shape of the via hole.

In a specific embodiment, the outer surface of the signal return is adhesively connected to the wall of the via.

In a specific embodiment, two of the at least two circuit layers are used for transmitting a high-speed signal, the two circuit layers for transmitting the high-speed signal are electrically connected through the signal transmission structure, and the length of the signal transmission structure is the same as the distance between the two circuit layers for transmitting the high-speed signal.

Compared with the prior art, the signal transmission structure of this application includes signal transmission portion, insulating part and signal backward flow portion, signal transmission portion is used for transmitting drive signal, the insulating part cladding in the surface of signal transmission portion, signal backward flow portion set up in the surface of insulating part for transmit backward flow signal, just signal backward flow portion's signal transmission direction with signal transmission portion's signal transmission direction is parallel and opposite, when transmitting high-speed signal, makes drive signal can circulate between two circuit layers through signal transmission portion, makes the backward flow signal can flow back the below of signal through signal backward flow portion, has avoided the impedance sudden change problem that high-speed signal trades the layer transmission and brings as early as possible, and need not to set up the earth hole, has reduced the occupation of base plate area, has reduced manufacturing cost.

Drawings

Fig. 1 is a cross-sectional view of a prior art via signaling structure.

Fig. 2(a) and 2(b) are top views of signal transmission structures for transmitting high-speed signals in the prior art.

Fig. 3 is a cross-sectional view of a signal transmission structure according to an embodiment of the present application.

Fig. 4 is another perspective sectional view of the signal transmission structure of fig. 3.

Fig. 5 is a cross-sectional view of a circuit structure provided in an embodiment of the present application.

The attached drawings are as follows:

1. a signal transmission structure; 11. a signal transmission section; 12. an insulating section; 13. a signal return section; 2. a substrate; 21. a via hole; 22. and a circuit layer.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

In the description of the present application, unless explicitly stated or limited otherwise, the terms "first", "second", and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means two or more unless specified or indicated otherwise; the terms "connected," "fixed," and the like are to be construed broadly and may, for example, be fixedly connected, detachably connected, integrally connected, or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present application, it should be understood that the terms "upper" and "lower" used in the description of the embodiments of the present application are used in a descriptive sense only and not for purposes of limitation. In addition, in this context, it will also be understood that when an element is referred to as being "on" or "under" another element, it can be directly on "or" under "the other element or be indirectly on" or "under" the other element via an intermediate element.

When the chip is used, the corresponding pins need to be led out to the printed circuit board, and the chip is connected to other chips, interfaces or passive devices through the printed circuit board to be made into modules, systems or products, so as to be used in various occasions.

For chips, the integration level of the current chip is higher and higher, the manufacturing process is more and more complex, one chip comprises a plurality of modules and functions, and the number of chip pins can reach thousands of times, so that most of the chips can not lead out all pins from the surface layer or complete connection, and part of the pins need to be led out from the inner layer or the bottom layer through via holes, so that signal layer change transmission occurs; part of the product also has multiple signal layer change transmissions.

For the printed circuit board, along with the function of the circuit becoming more and more powerful, the printed circuit board usually needs to be provided with a plurality of circuit layers, and the circuit layers may need to be electrically connected, so that a through hole needs to be formed in the substrate of the printed circuit board, and the circuit layers which need to be electrically connected can be electrically connected through the through hole, that is, the situation of signal layer change transmission occurs.

When the electric signal is transmitted on the circuit board, the flow direction of the signal starts from the driver, flows to the load end along the routing on the printed circuit board; and then from the load end to the drive end along the ground plane through the shortest path or the path with the minimum impedance, and for the signals with higher speed (high-speed signals), the shortest path (with the minimum impedance) is often just on the reference ground right below the transmission line.

When the electrical signal trades the layer, the backward flow route of signal, reference plane have all changed, will appear the impedance sudden change, and in order to avoid the impedance sudden change problem that high-speed signal trades the transmission of layer and brings, prior art increases the earth hole near the signal trades the layer usually of base plate, lets the backward flow route return to the below of signal as early as possible, consequently need be provided with the earth hole, and it is big to occupy the base plate area, and manufacturing cost is high.

Specifically, referring to fig. 1, fig. 1 is a cross-sectional view of a prior art via signal transmission structure. In order to facilitate the connection of the printed wires between the circuit layers 22 ' in the substrate 2 ', in the prior art, a via hole 21 ' (signal hole) is generally drilled at the intersection of the wires to be connected of the circuit layers 22 ', and a connection wire 3 ' (metal wire) is disposed on the hole wall 211 ' of the via hole 21 ', and the circuit layer 22 ' to be connected extends out of a pad 221 ', and is electrically connected to the connection wire 3 ' through the pad 221 ', so that the circuit layers 22 ' to be electrically connected are electrically connected to each other through the via hole 21 '. The circuit layer 22 ' which is not required to be connected with the hole wall 211 ' of the via hole 21 ' needs to keep a preset distance, and the specific preset distance is set according to actual needs.

For the transmission of high-speed signals, on the one hand, in order to make the return path return to the lower side of the signal as soon as possible, in the prior art, a ground hole is generally further arranged near the via hole 21', and the arrangement of the ground hole occupies a larger area of the substrate, which is not favorable for the miniaturization design of the circuit. On the other hand, the driving terminals of the chips all have output impedance with a default value, and it is required that the traces on the printed circuit board also maintain the same impedance, so the positions of the ground holes cannot be randomly placed, and the distances between the signal holes and the ground holes and between the signal holes and the signal holes need to be determined according to simulation, as shown in fig. 2(a) and 2(b), fig. 2(a) and 2(b) are top views of a signal transmission structure for transmitting high-speed signals in the prior art.

Meanwhile, the via holes in the prior art are generally inductive, so that the distance between the via holes and the ground layer needs to be adjusted, the capacitance of the via holes is increased, and the characteristic impedance is consistent with the output impedance of the driving end. Specifically, simulation is required according to different lamination layers, different thicknesses, different plates, different impedance requirements and the like of the substrate, development cost is high, and the period is long.

Referring to fig. 3 and 4, fig. 3 is a cross-sectional view of a signal transmission structure according to an embodiment of the present application, and fig. 4 is a cross-sectional view of another perspective of the signal transmission structure in fig. 3. The signal transmission structure 1 is used for transmitting a high-speed signal (a high-speed signal is a digital signal with a relatively high transmission rate), and includes a signal transmission unit 11, an insulation unit 12, and a signal return unit 13. The signal transmission part 11 is used for transmitting a driving signal, the insulation part 12 covers the outer surface of the signal transmission part 11, the signal return part 13 is arranged on the outer surface of the signal insulation part 12 and used for transmitting a return signal, the length extending direction of the signal return part 13 is the same as that of the signal transmission part 11, and the signal transmission direction of the signal return part 13 is opposite to that of the signal transmission part 11.

This application makes drive signal can circulate between two circuit layers of base plate through signal transmission portion 11, makes the backward flow signal can flow back the below of signal as early as possible through signal backward flow portion 13, promptly, can transmit drive signal and backward flow signal simultaneously through this signal transmission structure 1, has avoided the impedance sudden change problem that high-speed signal trades layer transmission and brings, and need not to set up the ground hole, has reduced the occupation of base plate area, has reduced manufacturing cost. Meanwhile, as the ground hole is not required to be arranged, the distance between the signal hole and the ground hole is not required to be determined through simulation, the production efficiency is improved, and the development cost is reduced.

Specifically, the signal transmission portion 11 has a strip-shaped structure with a circular cross section, and the signal return portion 13 also has a strip-shaped structure with a circular cross section. The insulation part 12 is connected to the outer surface of the signal transmission part 11 by means of bonding, and the signal return part 13 is sleeved outside the insulation part 12 and connected to the outer surface of the insulation part 12 by means of bonding. The signal transmission part 11, the insulation part 12 and the signal return part 13 are connected together to form a product for transmitting high-speed signals, so that the signal transmission structure 1 can be independently applied to different occasions. Meanwhile, the signal transmission part 11 and the signal backflow part 13 are permanently separated through the insulation part 12, current flowing between the signal transmission part 11 and the signal backflow part 13 is avoided, and normal work of the signal transmission part 11 and the signal backflow part 13 is guaranteed.

In this embodiment, the signal transmission portion 11 may be made of metal (e.g., copper material) or made according to a printed circuit board circuit process, and may be solid or hollow, the signal return portion 13 may be made of metal (e.g., copper material) or made according to a printed circuit board circuit process, and the insulation portion 12 may be a printed circuit board medium, or may be made of other insulation materials such as resin and rubber.

Further, the distance between the signal return unit 13 and the signal transmission unit 11 is set according to actual needs, and is not limited herein.

Correspondingly, the embodiment of the present application further discloses a circuit structure, and fig. 5 is a cross-sectional view of the circuit structure provided in the embodiment of the present application, as shown in fig. 5. The circuit structure comprises a substrate 2 and the signal transmission structure 1 in the embodiment, the substrate 2 is provided with a via hole 21 and a plurality of circuit layers 22, the via hole 21 penetrates through the upper surface and the lower surface of the substrate 2, and the circuit layers 22 are sequentially arranged at intervals along the thickness direction of the substrate 2. The signal transmission structure 1 is disposed in the via hole 21, and a length extending direction of the signal transmission structure 1 is the same as a length extending direction of the via hole 21, the signal transmission structure 1 and the via hole 21 are coaxially disposed (that is, an axial line of the signal transmission structure 1 and a central line of the via hole are on the same straight line), and the circuit layers 22 for transmitting high-speed signals are electrically connected through the signal transmission structure 1.

This application combines together signal hole and the ground hole that is used for transmitting high-speed signal, form a new via hole, can transmit drive signal through this via hole, also enable backward flow signal to flow back to drive signal's below as early as possible, the production of the impedance sudden change's that high-speed signal trades the layer and brings problem has been avoided, near signal hole need not to set up the ground hole in addition again simultaneously and follows, the space has been saved, also need not to carry out the position of emulation in order to confirm the ground hole many times according to different printed circuit board panel and stromatolite, the development efficiency is improved, the development cost is reduced.

Specifically, the via hole 21 is a circular structure, and the size and the shape of the cross section of the signal transmission structure 1 correspond to the size and the shape of the via hole 21, so that the outer surface of the signal transmission structure 1 is in close contact with the hole wall of the via hole 21. Further, the outer surface of the signal return portion 13 is connected to the hole wall of the via hole 21 by means of adhesion.

For high-speed signals, generally, the signals are transmitted between at most two circuit layers, so that only two circuit layers among the plurality of circuit layers of the circuit structure are used for transmitting high-speed signals, and for convenience of connection, the length of the signal transmission structure 1 is the same as the distance between the two circuit layers used for transmitting high-speed signals, and both end portions of the signal transmission structure 1 are electrically connected to the two circuit layers used for transmitting high-speed signals, respectively.

In this embodiment, the circuit layers for transmitting high-speed signals are the circuit layer 22 located on the upper surface of the substrate 2 and the circuit layer 22 located on the lower surface of the substrate 2, the length of the signal transmission structure 1 is the same as the length of the via hole 21, and two end portions of the signal transmission structure 1 are respectively flush with the upper and lower surfaces of the substrate 2, the circuit layer 22 located on the upper surface of the substrate 2 is electrically connected with the upper end portion of the signal transmission structure 1, and the circuit layer 22 located on the lower surface of the substrate 2 is electrically connected with the lower end portion of the signal transmission structure 1.

In other embodiments, the length of the signal transmission structure 1 may be set to be greater than the spacing between two circuit layers for transmitting high-speed signals. During connection, a hollow may be disposed on the signal transmission structure 1, so that the circuit layer 22 for transmitting high-speed signals passes through the hollow and is electrically connected to the signal transmission portion 11.

The above description is only for the preferred embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.