JPH0897566A - Printed board - Google Patents

Abstract

(57) [Summary] [Object] To provide a highly reliable printed circuit board in which the inductance of the power supply / GND wiring of each part of the board is low and uniform. [Structure] The power supply / GND wirings 5 of each layer are formed in parallel line patterns having substantially the same pitch, and the directions of the parallel line patterns are shifted at right angles for each layer to combine them in a checkered pattern. The power supply / GND wirings 5 are connected to each other through the via holes 6 at positions where they cross each other. And the power supply / GND wiring 5 of each layer
The signal wiring 3 is provided while avoiding the via hole 6. As a result, the inductance of the power supply / GND wiring 5 of each part of the substrate is made substantially uniform, and the power supply / GND of each layer is
The electromagnetic effect between the wirings 5 can be reduced to reduce the value of the inductance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring structure of a printed circuit board in which signal wirings connected to mounted electronic parts and power supply and / or GND wirings are provided in multiple layers.

[0002]

2. Description of the Related Art Conventionally, when designing wiring on a printed circuit board, there is a tendency to give priority to signal wiring over power / GND wiring. For example, in a two-layer (double-sided) board, the power supply is placed in an empty space of each layer. / GND wiring is solidly provided, and in a multi-layer substrate with three or more layers, the power supply layer and the GND are internally provided.
And the D layer.

[0003]

However, in the conventional wiring structure of the printed circuit board as described above, the power supply / GND wiring is often divided by the signal wiring and the land clearance. As a result, the inductance of the power supply / GND wiring of each part of the board becomes uneven,
A part with high inductance is created, and when a large current flows through it, potential fluctuation occurs, which may cause strong radiation noise. Further, the GND potential becomes unstable, which causes malfunction.

The present invention has been proposed to solve such a problem, and an object thereof is to provide a highly reliable printed circuit board in which the inductance of the power supply / GND wiring of each part of the board is low and uniform. To do.

[0005]

In order to achieve the above object, in a printed circuit board according to the present invention, a power source for each layer and / or
Alternatively, the GND wirings are formed in parallel line patterns having substantially the same pitch, the directions of the parallel line patterns are shifted at right angles for each layer and combined in a checkerboard pattern, and the power supply and / or the GND wiring in each layer combined in the checkerboard pattern. Between
Connections were made through via holes at positions that intersect each other. Then, the signal wiring is provided while avoiding the power supply and / or the GND wiring of each layer and the via hole.

[0006]

In the printed circuit board having the above-mentioned wiring structure, the power supply and / or the GND wiring are provided substantially uniformly, and the parallel line patterns of the power supply and / or the GND wiring of each layer are oriented at right angles to each other. The inductance of the power supply and / or the GND wiring of each part of the substrate is substantially uniform, and the electromagnetic influence between the power supply and / or the GND wiring of each layer is small, so that the inductance value is also low.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing a wiring structure of a printed board according to the present invention, showing an example of a two-layer (double-sided) board.

As shown in the figure, the printed circuit board 1 is an IC
Signal wiring 3 connected to the electronic component 2 on the upper layer (upper surface) on which the electronic component 2 is mounted and the lower layer (lower surface) on the opposite side.
And a power supply / GND wiring (power supply and / or GND wiring) 5.

Power supply / GND wirings 5a and 5b of upper and lower layers
Are formed in parallel line patterns with their ends closed, and the directions of the parallel line patterns are shifted at right angles for each layer and are combined in a cross beam shape. That is, the power supply / GND wiring 5a in the upper layer is a parallel line pattern parallel to the longitudinal direction of the substrate 1, and the power supply / GND wiring 5b in the lower layer is the substrate 1
It is a parallel line pattern parallel to the lateral direction of. Further, the pitch P of the respective parallel line patterns is set to be substantially the same, and in the present embodiment, the pitch P is set to be substantially the same as the layer interval D, that is, the thickness of the substrate 1. In addition, the power supply / GND of each layer combined in a grid pattern
The wirings 5a and 5b are connected to each other through a large number of via holes 6 at positions where they intersect each other. Since the via holes 6 have substantially the same pitch P of the parallel line pattern of each layer, they are also arranged at substantially the same pitch.

The electronic component 2 and the signal wiring 3 are composed of the power source / GND wiring 5a of each layer forming the parallel line pattern,
5b and the via hole 6 connecting the layers are avoided. That is, the signal wiring 3 extending from the electronic component 2 is extended in the upper layer in parallel with the parallel line pattern of the power supply / GND wiring 5a in the upper layer, and the power supply / GND wiring 5a is formed.
When it is necessary to traverse the same, it is allowed to escape to the lower layer through the same via hole (not shown) in parallel with the via hole 6 and extends in parallel with the parallel line pattern of the power supply / GND wiring 5b in the lower layer. After that, it is returned to the upper layer through a via hole (not shown) at an appropriate position.

In the printed circuit board 1 having the above-mentioned wiring structure, the power supply / GND wirings 5 are provided substantially uniformly, and the parallel line patterns of the power supply / GND wirings 5a and 5b in the upper and lower layers are oriented at right angles to each other. Therefore, the inductance of the power supply / GND wiring 5 in each part of the substrate becomes substantially uniform, and the electromagnetic influence between the power supply / GND wirings 5a and 5b in each layer becomes small, so that the inductance value also becomes low. Further, if the pitch P of the parallel line pattern of each layer is substantially the same as the layer spacing D as in this embodiment,
The uniformity of inductance is further increased.

As described above, since the inductance of the power supply / GND wiring of each part of the substrate is low and uniform, radiation noise due to potential fluctuation and malfunction due to unstable GND potential are eliminated.

Of the multi-layer power supply / GND wiring 5,
By wiring the pattern in at least one layer only in the longitudinal direction of the substrate 1, for example, the signal pattern can be wired in the longitudinal direction of the substrate in the first layer and in the lateral direction of the substrate in the second layer. Each time it hits the pattern of the / GND wiring 5, it is not necessary to make a detour by the via hole 6, and the signal pattern can be efficiently wired.

In the present embodiment, the case of a two-layer board has been described, but in the case of a multi-layer board having three or more layers, the power supply / GND wirings of the respective layers are formed in parallel line patterns of substantially the same pitch and adjacent to each other. The directions of the parallel line patterns of the matching layers are shifted at right angles for each layer and combined in a cross beam pattern,
The power supply / GND wirings of the respective layers combined in the shape of a cross are connected through via holes at positions where they intersect with each other. Then, the signal wiring may be provided so as to avoid the power supply / GND wiring and the via hole in each layer. As a result, the inductance of the power supply / GND wiring of each part of the substrate can be made substantially uniform and low. Further, by setting the pitch of the parallel line pattern of each layer to be substantially the same as the layer interval, the uniformity of inductance can be further improved.

If a signal pattern having a portion for connecting a layer wired in parallel to the wiring direction of the power supply / GND wiring to another wiring layer as needed is provided, the component positions of the output and the input are arranged. Even if it is not on the extension line of the power supply / GND wiring, it is not necessary to cut back with a via hole, and therefore high density pattern wiring is possible. Furthermore, if the signal pattern is formed in parallel with the pattern of the power supply / GND wiring,
Higher density pattern wiring can be made, and as a result, the substrate size can be made smaller and noise can be reduced. In other words, noise is caused by signal wiring and power supply / GN.
Since it is proportional to the loop area formed with the D wiring, noise can be reduced if the loop area is reduced by a high-density pattern wiring.

[0017]

As described above, according to the present invention,
It is possible to realize a highly reliable printed circuit board in which the inductance of the power supply / GND wiring of each part of the board is low and uniform, thereby preventing generation of radiation noise and malfunction.

[Brief description of drawings]

FIG. 1 is a perspective view showing a wiring structure of a printed circuit board according to an embodiment of the present invention.

[Explanation of symbols]

 1 Printed Circuit Board 2 Electronic Component 3 Signal Wiring 5 (5a, 5b) Power / GND Wiring 6 Via Hole

(72) Inventor Yasushi Takeuchi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Toru Osaka, 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yoshimi Terayama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (3)

[Claims] 1. A printed circuit board comprising electronic components mounted thereon, and a signal wiring for connecting to the mounted electronic components and a power supply and / or GND wiring provided in multiple layers, wherein the power supply and / or GND wiring of each layer is substantially The power source and / or GN of each layer are formed in parallel line patterns having the same pitch, and the directions of the parallel line patterns are shifted at right angles for each layer, and are combined in a checkerboard pattern.
The D wirings are connected to each other through via holes at positions where they intersect with each other, and the signal wirings are provided while avoiding the power supply and / or GND wirings of the respective layers and the via holes. Printed board. 2. The printed circuit board according to claim 1, wherein at least one layer of the multi-layered power supply and / or GND wiring is provided with a pattern only in the longitudinal direction of the board. 3. A signal pattern having a portion for connecting a layer wired in parallel with the wiring direction of the power supply and / or the GND wiring to another wiring layer as required. The printed circuit board according to 1 or 2.