Wiring structure for improving high-speed signal loss for high-speed circuit board

Abstract

The utility model relates to a wiring structure for improving high-speed signal loss for a high-speed circuit board. The wiring structure comprises two differential lines which are symmetrically arranged in parallel, each differential line structurally comprises a first signal line and a second signal line which are parallel to each other, and the first signal line and the second signal line are connected through a connecting signal line. The first signal line is arranged in a BGA area of the high-speed circuit board, and the second signal line is arranged in a non-BGA area of the high-speed circuit board; the first signal line and the second signal line simultaneously meet the differential impedance requirement of the high-speed circuit board, and meanwhile, the line width of the first signal line is smaller than that of the second signal line; the line distance between the two first signal lines is smaller than the line distance between the two second signal lines. By arranging the first signal line, the second signal line and the connecting signal line, the signal loss of the high-speed printed board under a high-frequency signal can be improved, so that the high-frequency signal transmission performance of the high-speed printed board is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of high-speed circuit boards, in particular to a wiring structure for improving high-speed signal loss for high-speed circuit boards. Background Art

[0002] BGA packaging is a commonly used packaging form for high-speed circuit boards, with the advantages of small size, many pins, good signal integrity and heat dissipation performance. As high-speed circuit boards develop towards integration and high speed, high-speed circuit boards often use differential lines for signal transmission, which are used to transmit signals with a phase difference of 180 degrees, improving the anti-interference ability of high-speed circuit boards.

[0003] In the prior art, the differential lines on high-speed circuit boards have the same line width in the BGA area and the non-BGA area. This form of wiring will cause additional signal loss to high-frequency signals due to line width limitations. The higher the signal rate, the greater the loss, making it difficult to meet the needs of high-frequency signals. Utility Model Content

[0004] In view of the shortcomings in the above-mentioned existing production technology, the applicant provides a routing structure for improving high-speed signal loss for a high-speed circuit board. By setting a first signal line, a second signal line and a connecting signal line, the signal loss of the high-speed printed circuit board under high-frequency signals can be improved, thereby improving the performance of the high-speed printed circuit board in high-frequency signal transmission.

[0005] The technical solution adopted by the utility model is as follows:

[0006] A routing structure for improving high-speed signal loss for a high-speed circuit board includes two differential lines arranged symmetrically and in parallel;

[0007] The structure of a single differential line is: comprising a first signal line and a second signal line parallel to each other, wherein the first signal line and the second signal line are connected via a connecting signal line;

[0008] The first signal line is arranged in a BGA area of ​​the high-speed circuit board, and the second signal line is arranged in a non-BGA area of ​​the high-speed circuit board;

[0009] The first signal line and the second signal line simultaneously meet the differential impedance requirements of the high-speed circuit board, and the line width of the first signal line is smaller than the line width of the second signal line;

[0010] The line distance between the two first signal lines is smaller than the line distance between the two second signal lines.

[0011] As a further improvement of the above technical solution:

[0012] The routing structure reduces signal loss in the 25 GHz-100 GHz frequency band.

[0013] The first signal lines of the two differential lines have the same length, and the second signal lines of the two differential lines have the same length.

[0014] The two differential lines are of equal length.

[0015] The single connection signal line is arranged obliquely, and the angle between the single connection signal line and the corresponding first signal line is in the range of 120°-150°.

[0016] The BGA region of the high-speed circuit board includes a plurality of via holes, and the via holes correspond to the pads on the surface layer of the high-speed circuit board.

[0017] The differential lines are arranged on a signal layer of a high-speed circuit board.

[0018] The beneficial effects of the utility model are as follows:

[0019] The utility model has a compact and reasonable structure and is easy to operate. By setting a first signal line, a second signal line and a connecting signal line, it can meet the small line width routing of the differential line in a small-pitch BGA area, and at the same time can reduce the signal loss of the differential line, thereby improving the performance of the differential line and improving the performance of the high-speed circuit board.

[0020] The utility model also has the following advantages:

[0021] (1) The wiring structure of the utility model can significantly reduce signal loss in the 25GHz-100GHz frequency band and is suitable for the use of high-frequency signals.

[0022] (2) The utility model has a simple structure and compact layout, and can meet the requirements of high-speed circuit board integration and high-speed use.

[0023] (3) The wiring structure of the present invention does not have high requirements on the manufacturing process and will not introduce additional production costs. It can greatly improve the performance of high-speed circuit boards while ensuring production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the utility model.

[0025] Figure 2 for Figure 1 A partial enlarged view of point A in the middle.

[0026] Among them: 1. First signal line; 2. Second signal line; 3. Connecting signal line; 4. Via hole; 5. High-speed circuit board. DETAILED DESCRIPTION

[0027] The specific implementation of the present utility model is described below in conjunction with the accompanying drawings.

[0028] The structure and functions of the utility model are as follows:

[0029] like Figure 1-Figure 2 As shown, a routing structure for improving high-speed signal loss for a high-speed circuit board includes two symmetrically and parallelly arranged differential lines; the structure of a single differential line is: including a first signal line 1 and a second signal line 2 that are parallel to each other, and the first signal line 1 and the second signal line 2 are connected by a connecting signal line 3; the first signal line 1 is arranged in the BGA area of ​​the high-speed circuit board 5, and the second signal line 2 is arranged in the non-BGA area of ​​the high-speed circuit board 5; the first signal line 1 and the second signal line 2 simultaneously meet the differential impedance requirements of the high-speed circuit board 5, and at the same time, the line width of the first signal line 1 is smaller than the line width of the second signal line 2; the line spacing between the two first signal lines 1 is smaller than the line spacing between the two second signal lines 2. The routing structure of the utility model is aimed at improving the signal loss of high-speed signals, especially being able to reduce the signal loss of signals in the 25GHz-100GHz frequency band, thereby improving the performance of the differential line and improving the performance of the high-speed circuit board 5.

[0030] The wiring structure of the utility model includes two differential lines of equal length, and both differential lines are arranged on the signal layer of the high-speed circuit board 5;

[0031] The high-speed circuit board 5 includes a BGA area and a non-BGA area. The BGA area of ​​the high-speed circuit board 5 includes a plurality of vias 4, and the vias 4 correspond to the pads on the surface of the high-speed circuit board 5. The vias 4 are used for inter-layer signal connection.

[0032] Since a plurality of vias 4 are provided in the BGA region of the high-speed circuit board 5, in order to improve the wiring efficiency, under the condition of meeting the differential impedance requirement of the high-speed circuit board 5, the line width and line spacing of the first signal lines 1 of the two differential lines are as small as possible to reduce the volume of the high-speed circuit board 5 and improve the wiring density;

[0033] In order to reduce the impact of high-density wiring on the signal transmission capability of the high-speed circuit board 5, in the non-BGA area, while meeting the differential impedance requirements of the high-speed circuit board 5, the line width and line spacing of the second signal lines 2 of the two differential lines are as large as possible, thereby improving the signal transmission performance of the high-speed circuit board 5.

[0034] The two differential lines are parallel to each other, of equal length, and arranged symmetrically;

[0035] The first signal lines 1 of the two differential lines are of equal length, the second signal lines of the two differential lines are of equal length, and correspondingly, the connecting signal lines 3 of the two differential lines are of equal length;

[0036] The single connecting signal line 3 is arranged obliquely, such as Figure 2 As shown, the included angle θ between the connecting signal line 3 and the corresponding first signal line 1 is in the range of 120°-150°.

[0037] The following is the specific examples section.

[0038] Embodiment 1:

[0039] The high-speed circuit board 5 is used as a 6U board, such as Figure 2 As shown, the design requirements are:

[0040] In the BGA area, the maximum spacing L between two adjacent vias 4 is 39.37 mil;

[0041] In the BGA area, the pad diameter D of a single via 4 is 18 mil;

[0042] The differential signal impedance requirement Z is 100Ω;

[0043] The minimum wire-to-reel spacing requirement is 4 mil;

[0044] It can be obtained that: for a single differential line, the line width W1 of the first signal line 1 is 4 mil, the line width W2 of the second signal line 2 is 6 mil, the line width of the connecting signal line 3 is the same as the line width W1 of the first signal line 1, and there is a smooth transition between the connecting signal line 3 and the first signal line 1, and between the connecting signal line 3 and the second signal line 2;

[0045] The line spacing S1 between the first signal lines 1 of the two differential lines is 5.3 mil, and the line spacing S2 between the second signal lines 2 of the two differential lines is 10 mil;

[0046] The angle θ between the connecting signal line 3 and the corresponding first signal line 1 is 135°, and this requirement can be met by adjusting the length of the connecting signal line 3;

[0047] In addition, it is also necessary to ensure that (LD-2*W1-S1) / 2 can meet the minimum wire-reel spacing requirements;

[0048] In this embodiment, (LD-2*W1-S1) / 2=4.035mil, which meets the requirement of 4mil minimum wire-to-reel spacing;

[0049] The high-speed circuit board 5 printed with the routing structure of this embodiment is subjected to an insertion loss test. The frequency band of the test signal is 25 GHz, and its S parameters are extracted. Compared with the traditional differential line, the test results show that the routing structure of this embodiment can significantly improve the insertion loss of the high-speed printed circuit board 5.

[0050] The above description is an explanation of the utility model, not a limitation of the utility model. The scope of the utility model is defined by the claims. Any form of modification can be made within the protection scope of the utility model.

Claims

1. A wiring structure for improving high-speed signal loss for a high-speed circuit board, characterized in that: It includes two differential lines which are symmetrically and parallelly arranged; The structure of a single differential line is as follows: comprising a first signal line (1) and a second signal line (2) which are parallel to each other, wherein the first signal line (1) and the second signal line (2) are connected via a connecting signal line (3); The first signal line (1) is arranged in a BGA area of ​​the high-speed circuit board (5), and the second signal line (2) is arranged in a non-BGA area of ​​the high-speed circuit board (5); The first signal line (1) and the second signal line (2) simultaneously meet the differential impedance requirements of the high-speed circuit board (5), and the line width of the first signal line (1) is smaller than the line width of the second signal line (2); The line distance between the two first signal lines (1) is smaller than the line distance between the two second signal lines (2).

2. The wiring structure for improving high-speed signal loss for a high-speed circuit board as claimed in claim 1, characterized in that: The routing structure reduces signal loss in the 25 GHz-100 GHz frequency band.

3. The wiring structure for improving high-speed signal loss for a high-speed circuit board as claimed in claim 1, characterized in that: The first signal lines (1) of the two differential lines are of equal length, and the second signal lines of the two differential lines are of equal length.

4. The wiring structure for improving high-speed signal loss for a high-speed circuit board as claimed in claim 1, characterized in that: The two differential lines are of equal length.

5. The wiring structure for improving high-speed signal loss for a high-speed circuit board as claimed in claim 1, characterized in that: The single connecting signal line (3) is arranged obliquely, and the angle between the single connecting signal line (3) and the corresponding first signal line (1) is in the range of 120°-150°.

6. The wiring structure for improving high-speed signal loss for a high-speed circuit board as claimed in claim 1, characterized in that: The BGA region of the high-speed circuit board (5) comprises a plurality of via holes (4), and the via holes (4) correspond to solder pads on the surface layer of the high-speed circuit board (5).

7. The wiring structure for improving high-speed signal loss for a high-speed circuit board as claimed in claim 1, characterized in that: The differential lines are arranged on a signal layer of a high-speed circuit board (5).

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