Patent Application
20220369451
The present disclosure relates to the field of communication device technology, and in particular to a circuit board and a communication device having the circuit board.
With the advent of the information era, the transmission speed of the signal increases constantly. A speed of a high-speed SerDes (SERializer/DESerializer) has been increased from 25 Gbps to 56 Gbps, and is increasing to 112 Gbps. With such a high speed, there are many design difficulties in implementing high-speed signal wiring throughout the system. In the past, design considerations were typically made at the component level, but a new generation of multi-Gbps designs require an overall analysis of paths of the signal channel. The developer must analyze and improve interactions of all components in the entire channel instead of focusing on just one component. In the process of the analyzing and improving, a crosstalk problem of the communication line is important which cannot be ignored.
Embodiments of the present disclosure provide a circuit board including a first signal line and a second signal line that are disposed adjacent to each other, a ground plane, and a conductive layer connected to the ground plane, where the conductive layer is disposed between the first signal line and the second signal line.
Embodiments of the present disclosure further provide a communication device including a housing and the circuit board, where the circuit board is disposed in the housing.
One or more embodiments are described as examples with reference to the corresponding figures in the accompanying drawings, and the examples do not constitute a limitation to the embodiments. Elements with the same reference numerals in the accompanying drawings represent similar elements. The figures in the accompanying drawings do not constitute a proportion limitation unless otherwise stated.
In order to make objectives, technical solutions and advantages of the present disclosure clearer, embodiments of the present disclosure will be described below in detail with reference to accompanying drawings and embodiments. It should be understood that, in various embodiments, many technical details are proposed for the reader to better understand the present disclosure. However, the technical solutions claimed in the present disclosure may be realized even without these technical details and various changes and modifications based on the following embodiments.
A first embodiment of the present disclosure relates to a circuit board including a first signal line and a second signal line that are disposed adjacent to each other, a ground plane, and a conductive layer connected to the ground plane. The conductive layer is disposed between the first signal line and the second signal line.
The circuit board is provided with a grounded conductive layer between the first signal line and the second signal line that are disposed adjacent to each other. When a signal propagates on the first signal line, a coupling electric field is formed between the first signal line and the conductive layer that is grounded, so that interference noise generated by the first signal line is transmitted to the grounded conductive layer adjacent to the first signal line, and then transmitted to a ground network via the grounded conductive layer, so that the grounded conductive layer shares the noise interference that would otherwise be concentrated on the second signal line, thereby greatly reducing interference influence on the second signal line and effectively reducing crosstalk problems of the communication line.
The implementation details of a non-contact detection apparatus in this embodiment are described in detail below, and the following contents are merely provided for convenient understanding of the implementation details, which are not necessary for implementing the technical solution.
As shown in
The ground plane 11 is a conductive metal layer inside the circuit board 10, which is configured to provide a ground to electronic components on the circuit board 10. In this embodiment, the circuit board 10 includes a substrate (not shown) configured to carry the ground plane 11, and a plurality of insulating layers and circuit layers configured to form a circuit connection structure are spaced apart from each other and sequentially stacked above the ground plane 11 on the substrate.
The first signal line 12 is a conductor track formed inside the circuit board 10 and may be formed by etching the circuit layer of the circuit board 10. The first signal line 12 shown in
The second signal line 13 is also a conductor track formed inside the circuit board 10, and the second signal line 13 shown in
The conductive layer 14, which may be a conductor track electrically connected to the ground plane 11 through a ground via 140, is of the same layer of the circuit board 10 as the first signal line 12. In this embodiment, the conductive layer 14 is parallel to the transmission line 121 and the transmission line 122. Specifically, in this embodiment, there are two ground vias 140, and the two ground vias 140 are located at two side of the conductive layer 14, respectively.
It should be noted that the first signal line 12, the second signal line 13, and the conductive layer 14 may be respectively disposed at different layers of the circuit board 10, or any two of them may be of the same layer of the circuit board 10 and the other is disposed at the other layer of the circuit board 10, or all of the them may be of the same layer of the circuit board 10. In this embodiment, the conductive layer 14 and the first signal line 12 are of the same layer, so that the grounded conductive layer 14 and the first signal line 12 are relatively close to each other because they are of the same layer, thereby enhancing the coupling degree between the first signal line 12 and the conductive layer 14, enabling the grounded conductive layer 14 to share more noise interference, and reducing the interference influence on the second signal line 13 to a greater extent.
For example, as shown in
In this embodiment, the conductive layer 14, the first signal line 12, and the second signal line 13 are all of the same layer of the circuit board 10. Since the presence of the conductive layer 14 is able to reduce the degree of interference to which the second signal line 13 is subjected, the second signal line 13 is no longer forced to form on other layers of the circuit board 10 due to the interference, thereby saving the number of wiring layers to reduce the cost. In addition, it should be noted that thicknesses of the conductive layer 14 and the transmission lines 121, 122 may be completely the same (i.e., the thicknesses of all the three layers are the same), partially the same (i.e., the thicknesses of any two of the three layers are the same), or different from each other (i.e., the thicknesses of all the three layers are different), which is not specifically limited herein. In an actual manufacturing process, the thicknesses of the conductive layer 121 and the transmission lines 121 and 122 may be appropriately selected with reference to specific design schemes and manufacturing process requirements. In this embodiment, the thicknesses of the conductive layer 121 and the transmission lines 121 and 122 are the same.
The inventor of the present disclosure performs crosstalk measurement and comparison on a high-speed board having the above-described structure. In this board, outlet layers of the signal vias of the first signal line and the second signal line are both L8 layers, and a pitch of a ball grid array (BGA) is 1.0 mm. An experimental result is shown in
A second embodiment of the present disclosure relates to another circuit board 20. As shown in
Specifically, the first signal line 12 includes a single transmission line 121, a signal via 123 is provided on one side of the transmission line 121, and the transmission line 121 is connected to the signal via 123 through a connection line 125, so that the transmission line 121 communicates with conductor tracks on other circuit layers of the circuit board 20 through a conductive pattern 125 and the single signal via 123.
The second signal line 13 is a conductor track formed inside the circuit board 20, and includes a transmission line 131 and a transmission line 132 that are spaced apart from each other. A signal via 133 is provided on one side of the transmission line 131, the transmission line 131 is connected to the signal via 133 through a connection line 135. A signal via 134 is provided on one side of the transmission line 132, and the transmission line 132 is connected to the signal via 134 through a connection line 136. Thus, the transmission line 131 and the transmission line 132 communicate with the conductor tracks on the other line layers of the circuit board 20 through the signal via 133 and the signal via 134, respectively, to achieve transmission of electrical signals. In this embodiment, the transmission line 131 and the transmission line 132 are differential signal transmission lines, and the transmission line 131 is parallel to the transmission line 132.
In this way, the conductive layer 132 disposed between the transmission line 121 and the transmission line 132 of the second signal line 13 is still able to share the noise interference that would otherwise be concentrated on the transmission line 132, thereby greatly reducing the interference influence on the transmission line 132 of the second signal line 13 and effectively reducing the crosstalk problem of the communication line.
A third embodiment of the present disclosure relates to still another circuit board 30. As shown in
Specifically, the circuit board 30 includes two ground vias 140 and a conductive pattern disposed between the two ground vias 140 and respectively connected to the two ground vias 140. In this embodiment, the conductive pattern includes a trapezoidal portion 141, a rectangular portion 142, a polygonal portion 143, a circular portion 144, a rectangular portion 145, a square portion 146, and a bent portion 147 that are sequentially connected from the ground via 140 at the top of the drawing shown in
In this way, although the conductive layer 14 has an irregular shape as a whole, it is still able to share the noise interference that would otherwise be concentrated on the transmission line 132, thereby greatly reducing the interference influence on the transmission line 132 of the second signal line 13 and effectively reducing the crosstalk problem of the communication line. It should be appreciated that an irregular design of the conductive layer 14 is not limited to the form provided in this embodiment as long as it is ensured that the conductive layer 14 is electrically connected to the ground plane 11 and disposed between the first signal line 12 and the second signal line 13.
A fourth embodiment of the present disclosure relates to still another circuit board 40. As shown in
Specifically, the third signal line 15 is a conductor track formed inside the circuit board 40, and includes a transmission line 151 and a transmission line 152 that are spaced apart from each other. The signal via 133 is provided on one side of a transmission line 151, and the transmission line 151 is connected to the signal via 133 through a connection line 155. The signal via 134 is provided on one side of a transmission line 152, and the transmission line 152 is connected to the signal via 134 through a connection line 156. Thus, the transmission line 151 and the transmission line 152 communicate with conductor tracks on the other line layers of the circuit board 40 through the signal via 133 and the signal via 134, respectively, to achieve transmission of electrical signals. In this embodiment, both the transmission line 151 and the transmission line 131 are connected to the signal via 133, and both the transmission line 152 and the transmission line 132 are connected to the signal via 134. The transmission line 151 and the transmission line 152 are also differential signal transmission lines, and the transmission line 151 is parallel to the transmission line 152.
It should be noted that the third signal line 15 and the second signal line 13 shown in
Since the grounded conductive layer 14 is also disposed between the transmission line 121 of the first signal line 12 and the transmission line 152 of the third signal line 15, a coupling electric field is formed between the transmission line 121 and the grounded conductive layer 14 when the signal propagates on the transmission line 121, so that interference noise generated by the transmission line 121 is transmitted to the conductive layer 14 adjacent to the transmission line 121, and then transmitted to the ground network via the conductive layer 14, so that the conductive layer 14 shares the noise interference that would otherwise be concentrated on the transmission line 152, greatly reduces the interference influence on the transmission line 132 of the third signal line 15, thereby effectively reducing the crosstalk problem of the communication line. In addition, the conductive layer is fully utilized so that it is able to simultaneously reduce the noise interference to both the second signal line 13 and the third signal line 15. It should be appreciated that the first signal line 12 and the second signal line 13 may also be disposed at different layers of the circuit board 40 when the circuit board 40 includes the first signal line 12, the second signal line 13, the conductive layer 14, and the third signal line 15 at the same time. In this embodiment, the third signal line 15 and the second signal line 13 may be disposed at the same layer or different layers of the circuit board 40.
It should be noted that the transmission lines 151, 152 of the third signal line 15 are not limited to be connected to the signal vias 133, 134 in the same manner as the transmission lines 131, 132 as described above. The transmission lines 151 and 152 may also be other signal transmission lines unrelated to the transmission lines 131 and 132, as shown in
A fifth embodiment of the present disclosure relates to still another circuit board 50. As shown in
In addition, a sixth embodiment of the present disclosure further provides a communication device 60 having the circuit board 10, as shown in
Those of ordinary skills in the art should understand that the embodiments described above are specific embodiments of the present disclosure, and in practical applications, various changes may be made to these embodiments in form and detail without departing from the spirit and scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201910916145.9 | Sep 2019 | CN | national |
The present disclosure is a United States National Stage Application filed under 35 U.S.C. § 371 of PCT Patent Application Serial No. PCT/CN2020/117493, filed Sep. 24, 2020, which claims priority to Chinese patent application No. 201910916145.9, filed Sep. 26, 2019, each of which is incorporated by reference herein in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2020/117493 | 9/24/2020 | WO |
