JP2003218481A - Printed circuit boards and printed circuit boards for mounting multi-pin connectors - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a multi-pin connector mounting printed board which suppresses signal reflections and minimums a distortion of a signal waveform. <P>SOLUTION: A signal line path near a region 11 on which a multi-pin connector is mounted is set as a part 6a of a narrow line path width and a signal line path of the other region 12 is set as a part 6b of a wide line path width. A dielectric 13 having a high dielectric constant is disposed in the region 11 on which the multi-pin connector is mounted, and a dielectric 14 having a low dielectric constant is disposed in the other region 12. An output reduction caused by a conductor loss is lessened and a change in characteristic impedance in a change part of the line path widths of the part 6a of the narrow line path width and the part 6b of the wide line path width can be mitigated, and it is possible to suppress reflections and suppress a distortion of a waveform. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed board and a printed board for mounting a multi-pin connector.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view showing a conventional printed circuit board for mounting a multi-pin connector. In the figure, 1 is a multi-pin connector, 2 is its connector pin, and 3 is a pin pitch. Further, 4 is a printed circuit board for mounting a multi-pin connector, 5
Is a through hole into which the connector pin 2 is inserted, 6 is a signal line connected to the through hole 5, 7 is a ground,
Reference numeral 8 is a dielectric provided between the grounds 7 so as to sandwich the signal line 6. FIG. 5 is a plan view showing a conventional printed circuit board for mounting a multi-pin connector. In the figure, 6a is a narrow portion of the signal line 6 connected to the through hole 5, and 6b is a line width of the signal line 6. It is a wide area. Figure 6
FIG. 4 is a characteristic diagram showing a relationship between frequency and conductor loss.

Next, the operation will be described. When mounting a multi-pin connector on a printed circuit board, it is necessary to pass a signal line between the multi-pins. Such a printed circuit board is, for example, “High-Speed Digital Desi”.
ne: Howard Johnson ”. FIG. 4 shows a method of mounting the multi-pin connector 1 on the multi-pin connector mounting printed board 4. The connector pins 2 of the multi-pin connector 1 are directly attached to the through holes 5 provided in the multi-pin connector mounting printed board 4. Therefore, the pin pitch 3 of the connector pins 2 and the pitch of the through holes 5 are the same. In order to increase the mounting density of the board, it is necessary to narrow the pin pitch 3 of the connector pins 2, that is, the pitch of the through holes 5, and the narrow pitch is about 2 mm to 1 mm. In FIG. 5, in order to pass the signal line 6 between the through holes 5 having a narrow pitch, it is necessary to narrow the line width of the signal line 6. On the other hand, when the line width of the signal line 6 becomes narrow,
The conductor loss of the signal line 6 becomes large. FIG. 6 is a characteristic diagram showing the relationship between the frequency and the conductor loss. Since the conductor loss is small when the frequency is low, it does not matter if the line width of the signal line 6 is narrow, but when the frequency is as high as 1 GHz. It is desirable that the line width of the signal line 6 is wide, because the conductor loss rapidly increases and leads to a decrease in signal amplitude. For this reason, in the vicinity of the through hole 5 in which the multi-pin connector 1 is mounted, the line width of the signal line 6 is set to the narrow portion 6a, and in other regions than that, the line width of the signal line 6 is set to the wide portion 6b. There is.

[0004]

Since the conventional printed circuit board for mounting a multi-pin connector is constructed as described above, when the frequency of the signal to be handled is high, the through hole 5 in which the multi-pin connector 1 is mounted is mounted. The line width of the signal line 6 is narrowed in the vicinity of
The track width is wide. However, in general, the inductance of the signal line 6 is inversely proportional to the line width, and the inductance is large in the narrow line width portion 6a and small in the wide line width portion 6b. In the portion where the line width changes from the portion 6b, there is a problem that the signal is reflected and waveform distortion occurs due to the change in the characteristic impedance, and the signal quality deteriorates.

The present invention has been made in order to solve the above problems, and reduces the change in characteristic impedance at the portion where the line width changes, suppresses signal reflection, and minimizes signal waveform distortion. It is intended to obtain a printed circuit board and a printed circuit board for mounting a multi-pin connector.

[0006]

In a printed circuit board according to the present invention, a portion having a narrow line width of a signal line is arranged on a dielectric having a large dielectric constant, and a portion having a wide line width is arranged on a dielectric having a small dielectric constant. It is equipped with a substrate.

The printed circuit board for mounting a multi-pin connector according to the present invention has a signal line in which the line width near the region where the multi-pin connector is mounted is narrowed and the line width outside the region is wide, and the line width of the signal line. And a substrate having a wide line width arranged on a dielectric having a small dielectric constant.

In the printed board for mounting a multi-pin connector according to the present invention, the line width of the signal line is gradually changed.

A printed circuit board for mounting a multi-pin connector according to the present invention includes a board in which a signal line whose line width is gradually changed is arranged on a dielectric whose dielectric constant is gradually changed.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below. Embodiment 1. 1 is a plan view showing a printed board for mounting a multi-pin connector according to Embodiment 1 of the present invention,
In the figure, 5 is a through hole, 11 is a region in which a multi-pin connector is mounted, 12 is another region, and 6a is a region 11 in which a multi-pin connector is mounted. A portion with a narrow line width, 6b is a portion with a wide line width of the signal line provided in the other region 12. Further, 13 is a dielectric (board) having a large dielectric constant arranged in the region 11 where the multi-pin connector is mounted,
Reference numeral 14 is a dielectric (substrate) arranged in the other region 12 and having a small dielectric constant.

Next, the operation will be described. As shown in FIG. 1, the line width of the signal line in the region 11 in which the multi-pin connector is mounted is made narrower than the line width of the signal line in the other region 12, and the dielectric constant of the narrow line width portion is It should be larger than the dielectric constant of the wide part. With this configuration, it is possible to widen the line width of the signal line in most of the region 12 other than the region 11 in which the multi-pin connector is mounted, and reduce the output decrease due to the conductor loss even if the signal frequency is high. You can Further, the inductance is large in the portion 6a where the line width is narrow, and the inductance is small in the portion 6b where the line width is wide. However, in the portion 6a where the line width is narrow, a large capacitance is generated between the portion 6a having a large dielectric constant and the ground, and the portion 6b where the line width is wide.
Then, a small dielectric constant causes a small capacitance to the ground. Therefore, due to the cancellation of the inductance and the capacitance, the line width changing portion between the narrow line width portion 6a and the wide line portion 6b is
Changes in the characteristic impedance are alleviated, reflection can be suppressed, and waveform distortion can be suppressed. The printed board for mounting the multi-pin connector may be a microstrip board, a tri-plate board, or another board.

Embodiment 2. 2 is a plan view showing a printed board for mounting a multi-pin connector according to Embodiment 2 of the present invention. In FIG. 2, reference numeral 15 is provided at a boundary between a region 11 where a multi-pin connector is mounted and another region 12. The tapered portion gradually changes the line width of the signal line. Other configurations are the same as those in FIG.

Next, the operation will be described. In the above-described first embodiment, as shown in FIG. 1, since the line width changes rapidly between the narrow line width portion 6a and the wide line portion 6b of the signal line, the line width changes to a signal. There is a concern that mode conversion will occur and a higher-order mode will occur. Therefore, the narrow portion 6a and the wide portion 6b of the signal line
A taper portion 15 that gradually changes the line width is provided at the part where the line width changes. According to this configuration, by gradually changing the line width, the change in the inductance in the changing portion of the line width is alleviated, the change in the characteristic impedance is further alleviated, reflection can be suppressed, and waveform distortion can be suppressed. . In addition, mode conversion of signals can be relaxed and occurrence of higher-order modes can be reduced.

Embodiment 3. 3 is a plan view showing a multi-pin connector mounting printed circuit board according to a third embodiment of the present invention. In the figure, 16 is arranged at the boundary between a region 11 where the multi-pin connector is mounted and another region 12. , A dielectric constant changing portion made of a dielectric material whose dielectric constant is gradually changed. Other configurations are the same as those in FIG.

Next, the operation will be described. As shown in FIG. 3, the narrow portion 6a and the wide portion 6b of the signal line are provided.
A taper portion 15 for gradually changing the line width is provided at a portion where the line width changes with, and a dielectric constant made of a dielectric material having a dielectric constant gradually changed according to the change in the line width of the taper portion 15. The changing portion 16 is arranged. According to this configuration, since the dielectric constant is gradually changed according to the change of the line width, the change of the characteristic impedance can be extremely reduced, the reflection can be suppressed, and the waveform distortion can be suppressed.
In addition, since the electromagnetic field distribution of the signal gradually changes, mode conversion can be suppressed and generation of higher-order modes can be eliminated.

[0016]

As described above, according to the present invention, in the printed circuit board, the portion of the signal line having a narrow line width is arranged on the dielectric having a large dielectric constant, and the portion of the signal line having a wide line width has a small dielectric constant. Since it is configured to include the substrate arranged in the body, it is possible to reduce the change in the characteristic impedance at the portion where the line width changes, suppress reflection, and minimize the waveform distortion.

According to the present invention, in the printed circuit board for mounting a multi-pin connector, the signal line in which the line width near the region where the multi-pin connector is mounted is narrowed and the line width outside the region is wide, and the signal line Since the part with the narrow line width is placed on the dielectric with a large dielectric constant and the part with the wide line width is placed on the dielectric with a small dielectric constant, it is configured near the area where the multi-pin connector is mounted. It is possible to widen most of the line width other than the above, and it is possible to reduce the output decrease due to the conductor loss even when the signal frequency becomes high. Further, it is possible to reduce the change in the characteristic impedance at the portion where the line width changes, suppress reflection, and minimize the waveform distortion.

According to the present invention, since the line width of the signal line is gradually changed in the printed board for mounting a multi-pin connector, the change in the characteristic impedance at the portion where the line width changes is further reduced. In addition to that, it is possible to reduce the occurrence of high-order modes.

According to the present invention, in the printed board for mounting a multi-pin connector, the signal line whose line width is gradually changed is arranged on the dielectric whose temperature is gradually changed. Therefore, it is possible to further reduce the change in the characteristic impedance in the portion where the line width and the dielectric constant change, and it is possible to prevent the higher-order mode from occurring.

[Brief description of drawings]

FIG. 1 is a plan view showing a multi-pin connector mounting printed circuit board according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a multi-pin connector mounting printed circuit board according to a second embodiment of the present invention.

FIG. 3 is a plan view showing a multi-pin connector mounting printed circuit board according to a third embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a conventional printed circuit board for mounting a multi-pin connector.

FIG. 5 is a plan view showing a conventional printed circuit board for mounting a multi-pin connector.

FIG. 6 is a characteristic diagram showing the relationship between frequency and conductor loss.

[Explanation of symbols]

1 multi-pin connector, 2 connector pins, 3 pin pitch, 4 multi-pin connector mounting printed circuit board, 5 through holes, 6 signal lines, 6a narrow part, 6b wide part, 7 ground, 8 dielectric, 11, 12 area,
13, 14 Dielectric (substrate), 15 Tapered part, 16
Dielectric constant changing part.

Claims (4)

[Claims] 1. A signal line having a narrow line width portion and a wide line portion, and a narrow line width portion of the signal line is disposed on a dielectric having a large dielectric constant, and a wide line width portion having a small dielectric constant. A printed circuit board having a substrate arranged on a dielectric. 2. A signal line having a narrow line width in the vicinity of a region where a multi-pin connector is mounted and a line width outside the region, and a dielectric having a large dielectric constant in a portion of the signal line having a narrow line width. And a printed circuit board for mounting a multi-pin connector, the printed circuit board having a wide line width arranged on a dielectric having a small dielectric constant. 3. The printed board for mounting a multi-pin connector according to claim 2, wherein the line width of the signal line is gradually changed. 4. The printed circuit board for mounting a multi-pin connector according to claim 3, wherein the board has a signal line whose line width is gradually changed and which is arranged on a dielectric whose dielectric constant is gradually changed. .