CN113473724A

CN113473724A - Printed circuit board and wiring method thereof

Info

Publication number: CN113473724A
Application number: CN202110939799.0A
Authority: CN
Inventors: 蔡元元; 王志钢; 皮本元
Original assignee: Spreadtrum Communications Shanghai Co Ltd
Current assignee: Spreadtrum Communications Shanghai Co Ltd
Priority date: 2021-08-16
Filing date: 2021-08-16
Publication date: 2021-10-01
Anticipated expiration: 2041-08-16
Also published as: CN113473724B; WO2023019864A1

Abstract

The application provides a printed circuit board and a printed circuit board wiring method, wherein the printed circuit board comprises a wiring layer and a ground plane layer which are arranged in a stacked mode, the wiring layer is provided with a first signal wire, the first signal wire is bent to form at least one groove area, and each groove area comprises an opening and a bottom; a shielding component is arranged in a first groove area of the at least one groove area, a through hole is formed in the shielding component, the through hole is located at the opening of the first groove area, and the shielding component is connected with the system ground of the ground plane layer through the through hole. The method and the device are favorable for improving the electromagnetic shielding effect between the serpentine signal lines of the printed circuit board and improving the crosstalk problem of the serpentine signal lines.

Description

Printed circuit board and wiring method thereof

Technical Field

The present disclosure relates to printed circuit boards, and particularly to a printed circuit board and a wiring method thereof.

Background

With the development of 5G (5th Generation Mobile Communication, fifth Generation Mobile Communication Technology), the requirement for high-speed signal transmission is higher, and when designing a high-speed PCB (Printed Circuit Board), in order to meet the timing requirement of high-speed signals, it is necessary to perform equal-length routing of signals.

At present, a snakelike routing mode is usually adopted, and a signal wire with a shorter total length in a group of signal wires is wound to a length tolerance range of the longest signal wire in the group, so as to control the time delay. However, crosstalk may occur in a portion of the serpentine trace where the signal lines are very close to each other (due to the close distance between the lines, signals on the trace may be spatially coupled to some adjacent transmission lines, which is called crosstalk), and the crosstalk may affect not only the voltage amplitude on the victim line, but also the transmission delay of signals on the victim line, which may affect the signal quality.

Disclosure of Invention

The embodiment of the application provides a printed circuit board and a printed circuit board wiring method, so that the electromagnetic shielding effect between serpentine signal lines of the printed circuit board is expected to be improved, and the crosstalk problem of the serpentine signal lines is improved.

In a first aspect, the present application provides a wiring method for a printed circuit board, the printed circuit board including a wiring layer and a ground plane layer, the wiring layer being stacked, the wiring layer being provided with a first signal line, the first signal line being bent to form at least one groove region, each groove region including an opening and a bottom; the method comprises the following steps:

providing a shielding member in a first groove region of the at least one groove region;

a through hole is formed in the shielding component and is positioned at the opening of the first groove area;

connecting the shielding component to the system ground of the ground plane layer through the through hole.

Optionally, each groove region in the at least one groove region is the first groove region.

Optionally, the method further includes: and opening the ground line at the bottom of the first groove region.

Optionally, the shielding component is a ground wire; or the shielding part is a copper sheet.

Optionally, the first signal line is a single-ended signal line; or, the first signal line is a differential signal line, the opening direction of the first groove region deviates from the second signal line, and the second signal line is another differential signal line forming a differential signal line group with the first signal line.

In a second aspect, the present application provides a printed circuit board, including a wiring layer and a ground plane layer, which are stacked, wherein the wiring layer is provided with a first signal line, the first signal line is bent to form at least one groove region, and each groove region includes an opening and a bottom;

a shielding component is arranged in a first groove area of the at least one groove area, a through hole is formed in the shielding component, the through hole is located at the opening of the first groove area, and the shielding component is connected with the system ground of the ground plane layer through the through hole.

It can be seen that, in the embodiment of the present application, the shielding component is disposed in the groove region formed by bending the serpentine signal line of the wiring layer of the printed circuit board, the through hole is disposed on the shielding component, and the through hole is located at the opening of the groove region, and then the shielding component is connected to the system ground of the ground plane layer of the printed circuit board through the through hole, which is beneficial to improving the electromagnetic shielding effect between the serpentine signal lines and improving the crosstalk problem of the serpentine signal line.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic flowchart of a wiring method for a printed circuit board according to an embodiment of the present disclosure;

fig. 2 is a schematic position diagram of a shielding member according to an embodiment of the present application;

fig. 3 is a simulation diagram of a wiring structure of a printed circuit board according to an embodiment of the present application;

FIG. 4 is a schematic diagram of port voltages in a wiring structure simulation diagram of a printed circuit board according to an embodiment of the present application;

fig. 5 is a schematic diagram illustrating a simulation result of a wiring structure of a printed circuit board according to an embodiment of the present disclosure;

FIG. 6 is a schematic illustration of the position of another shielding member provided by an embodiment of the present application;

FIG. 7 is a schematic illustration of the position of another shielding member provided by an embodiment of the present application;

FIG. 8 is a schematic illustration of the position of another shielding member provided by an embodiment of the present application;

fig. 9 is a schematic position diagram of another shielding member according to an embodiment of the present application.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth to provide a thorough understanding of the present application, and in the accompanying drawings, preferred embodiments of the present application are set forth. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. This application is capable of embodiments in many different forms than those described herein and those skilled in the art will be able to make similar modifications without departing from the spirit of the application and it is therefore not intended to be limited to the specific embodiments disclosed below.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise. In the description of the present application, "a number" means at least one, such as one, two, etc., unless specifically limited otherwise.

As shown in fig. 1, an embodiment of the present application provides a wiring method for a printed circuit board, where the printed circuit board includes a wiring layer and a ground plane layer, the wiring layer is provided with a first signal line, the first signal line is bent to form at least one groove region, and each groove region includes an opening and a bottom; the method comprises the following steps:

step 101, arranging a shielding component in a first groove area in the at least one groove area;

102, forming a through hole in the shielding component, wherein the through hole is positioned at the opening of the first groove area;

and 103, connecting the shielding component with the system ground of the ground plane layer through the through hole.

Specifically, referring to fig. 2, the first signal line may be a signal line adopting a serpentine routing manner, as shown by a gray line in fig. 2, the first signal line is bent to form at least one groove region, one end of each groove region enclosed and closed by the first signal line is a bottom of the groove region, and one end of each groove region not enclosed by the first signal line is an opening of the groove region.

Taking the area 1 indicated in fig. 2 as a first groove area as an example, a shielding member 2 is disposed in the first groove area, a through hole 3 is formed on the shielding member 2, and the through hole 3 is located at an opening of the first groove area 1. The shielding component 2 can be connected with the ground plane layer of the printed circuit board nearby through the through hole 3, so that the grounding path of the shielding component is reduced, the electromagnetic shielding effect is further improved, and the problem of crosstalk between signal lines is solved.

The opening of the through hole is not particularly limited, and the shielding member may be connected to the ground plane layer through the through hole.

In a specific implementation, since the diameter of the through hole is usually much larger than the diameter of the signal line, and the serpentine wiring itself occupies a larger space of the printed circuit board, in consideration of saving the wiring space, the width of the signal line gap of the serpentine wiring, that is, the width of each groove region formed by bending, usually does not exceed three times of the line width, sometimes the width of each gap may even adopt two times of the line width, that is, the diameter of the through hole may exceed the width of the first groove region, and at this time, the position setting of the through hole may specifically satisfy the following condition: the maximum width of the part of the through hole falling in the first groove area does not exceed the width of the first groove area, namely, the width of the first groove area does not need to be increased due to the through hole, and the through hole does not occupy excessive extra wiring space of the printed circuit board.

It should be noted that the first signal line shown in fig. 2 is only for illustrating the position of the shielding component, and in practical applications, the wiring structure of the first signal line is set according to the actual signal transmission requirement, and the specific bending wiring manner and the number of the groove regions formed by bending may be different from those shown in fig. 2; in addition, only one first groove region is exemplarily shown in fig. 2, and the number of the first groove regions may be greater in practical applications, for example, each groove region may be the first groove region, and is not specifically limited herein.

In some possible examples, each of the at least one groove region is the first groove region.

Specifically, each groove area in at least one groove area is a first groove area, namely, each groove area formed by bending the first signal line is provided with a shielding component, each shielding component is provided with a through hole, the position of each through hole is located at the opening of each groove area, each shielding component can be connected with the ground plane layer of the printed circuit board through the through hole arranged on the shielding component, namely, each shielding component is grounded nearby, and the path of grounding of each shielding component is shortened.

It can be seen that, in this example, each groove region in at least one groove region formed by bending the first signal line is the first groove region, that is, a shielding member is disposed in each groove region completely formed by the first signal line, and each shielding member is provided with a through hole, and each shielding member is grounded nearby, which is beneficial to further improving the electromagnetic shielding effect between the serpentine signal lines and improving the crosstalk problem between the signal lines.

In some possible examples, the method further comprises: opening the shielding member at the bottom of the first groove region.

In the concrete implementation, considering that the functions of the current terminals such as mobile phones are various, the number of electronic components of the printed circuit board in the terminal is more and more, but the size of the whole terminal is limited, the snake-shaped wiring can occupy a larger wiring space, and the through hole can occupy a larger wiring space, so that the shielding part at the bottom of the first groove area is opened, namely the through hole is not formed at the bottom of the first groove area (or other positions in the first groove area), and the space of the printed circuit board can be further saved.

Therefore, in this example, the shielding component at the bottom of the first groove region is open, which is beneficial to improving the electromagnetic shielding effect, improving the crosstalk problem between the serpentine signal lines, and saving the wiring space of the printed circuit board.

Alternatively, in other embodiments, if the printed circuit board has a relatively sufficient wiring space, the shielding member may have a plurality of through holes, the through holes may be located inside the first recessed area, for example, as shown by the signal lines between the

ports

1 and 2 in fig. 3, and the through holes may be located at the bottom of the first recessed area.

Specifically, fig. 3 shows three printed circuit board wiring structures, wherein, for a signal line a between a port 1 and a port 2, shielding members are respectively arranged in a plurality of groove regions formed by bending the signal line a, each shielding member is provided with two through holes, one through hole is located at the bottom of the groove region, and the other through hole is located at an opening of the groove region; for a signal wire b between the port 3 and the port 4, shielding parts are arranged in a plurality of groove areas formed by bending the signal wire b, each shielding part is only provided with one through hole, the through hole is positioned at the opening of the groove area, no through hole is arranged in the groove area, and the shielding part at the bottom of each groove area is open-circuited; for the signal line c between the port 5 and the port 6, a shielding member is not provided between the signal lines.

The three wiring structures shown in fig. 3 were simulated in accordance with the conditions shown in fig. 4, in which the voltages V1, V2, and V3 at port 1, port 3, and port 5 were the same in magnitude at the same time point, and R1, R2, and R3 were the same. The simulation results of the signals at the

ports

2, 4 and 6 are shown in fig. 5, where the black solid line is the simulation result of the port 6, the black dotted line is the simulation result of the port 4, and the gray solid line is the simulation result of the port 2, the horizontal axis represents the signal delay of the port, which is expressed in nS, and the vertical axis represents the port voltage amplitude, which is expressed in mV, as can be seen from fig. 5, the signals simulated at the

ports

2 and 4 are basically consistent in signal delay because the shielding component is arranged in the signal line gap, so that the electromagnetic coupling of the signals is reduced, and the signals simulated at the port 6 are not protected by crosstalk wiring, so that the electromagnetic capability portions are coupled with each other, so that the signals arrive before the delay is increased, and the control of the signal delay cannot be expected.

In some possible examples, the shielding member is a ground wire; or the shielding part is a copper sheet.

In a specific implementation, the conductive pattern of the shielding member may be in the form of a wire or a copper sheet.

Specifically, taking as an example that each groove region in at least one groove region is a first groove region, when the shielding member is a ground line, the arrangement of the shielding member may be as shown in fig. 6, where a gray line in fig. 6 is a first signal line, and a black line is a ground line; when the shielding member is a copper sheet, the shielding member may be disposed as shown in fig. 7. In fig. 7, the black line is the first signal line, and the shaded portion is the copper sheet.

In practical application, the width of the ground wire can be selectively set as required, the shielding component shown in fig. 6 is only used for describing the position of the shielding component, the width of the shielding component can be selected as required, and specifically, the width of the shielding component can be taken as large as possible under the condition of meeting the safety clearance of the conductive pattern.

It can be seen that in this example the shielding member may be a ground wire or a copper sheet, i.e. the form of the shielding member may be flexibly selected.

In some possible examples, the first signal line is a single-ended signal line; or, the first signal line is a differential signal line, the opening direction of the first groove region deviates from the second signal line, and the second signal line is another differential signal line forming a differential signal line group with the first signal line.

The single-ended signal line may be a single-ended high-speed signal line, and the differential signal line may be a differential high-speed signal line for transmitting a high-speed digital signal.

The at least one groove region formed by bending the second signal line may also include a first groove region, and an opening direction of the first groove region is away from the first signal line.

Specifically, referring to fig. 8 and 9, in at least one groove region formed by bending the first signal line, each groove region having an opening direction facing away from the second signal line may be the first groove region, and similarly, in at least one groove region formed by bending the second signal line, each groove region having an opening direction facing away from the first signal line may be the first groove region. Wherein, fig. 8 shows the shielding member in the form of a ground line, and in fig. 8, gray lines are a first signal line and a second signal line, and a black line is a ground line; the shielding member is shown in the form of a copper sheet in fig. 9, and black lines in fig. 9 are a first signal line and a second signal line, and a hatched portion is a copper sheet.

It can be seen that, in this example, the first signal line may be a single-ended signal line or a differential high-speed signal line, that is, the method may be applied to various types of signal lines to improve the crosstalk problem between the signal lines.

The embodiment of the application also provides a printed circuit board, which comprises a wiring layer and a ground plane layer which are arranged in a laminated mode, wherein the wiring layer is provided with a first signal wire, the first signal wire is bent to form at least one groove area, and each groove area comprises an opening and a bottom; a shielding component is arranged in a first groove area of the at least one groove area, a through hole is formed in the shielding component, the through hole is located at the opening of the first groove area, and the shielding component is connected with the system ground of the ground plane layer through the through hole.

In some possible examples, the shielding member at the bottom of the first recess region is open.

The above examples only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A printed circuit board wiring method is characterized in that the printed circuit board comprises a wiring layer and a ground plane layer which are arranged in a stacked mode, wherein the wiring layer is provided with a first signal wire, the first signal wire is bent to form at least one groove area, and each groove area comprises an opening and a bottom; the method comprises the following steps:

2. A printed circuit board routing method as in claim 1 wherein each of the at least one recessed area is the first recessed area.

3. The printed circuit board routing method of claim 1, further comprising:

and opening the ground line at the bottom of the first groove region.

4. The printed circuit board wiring method according to claim 1, wherein the shielding member is a ground line; or the shielding part is a copper sheet.

5. The printed circuit board wiring method of claim 1, wherein the first signal line is a single-ended signal line; or, the first signal line is a differential signal line, the opening direction of the first groove region deviates from the second signal line, and the second signal line is another differential signal line forming a differential signal line group with the first signal line.

6. A printed circuit board is characterized by comprising a wiring layer and a ground plane layer which are arranged in a stacked mode, wherein the wiring layer is provided with a first signal line, the first signal line is bent to form at least one groove area, and each groove area comprises an opening and a bottom;

7. The printed circuit board of claim 6, wherein each of the at least one recessed area is the first recessed area.

8. The printed circuit board of claim 6, wherein the shielding member at the bottom of the first recessed area is open-circuited.

9. The printed circuit board of claim 6, wherein the shielding member is a ground line; or the shielding part is a copper sheet.

10. The printed circuit board of claim 6, wherein the first signal line is a single-ended signal line; or, the first signal line is a differential signal line, the opening direction of the first groove region deviates from the second signal line, and the second signal line is another differential signal line forming a differential signal line group with the first signal line.