JPH0918156A - Multilayer printed wiring board - Google Patents

Abstract

PURPOSE: To decrease the inductance and combined resistance of the entire ground wiring by providing a first layer having first signal wiring part and first power supply wiring part, and a second layer connected with a plurality of first ground wiring parts, a second signal wiring part and a second power supply wiring part. CONSTITUTION: Wiring layers 16, 17 in the direction of X, Y axes having the wiring direction different by 90 deg. from each other are laminated through an insulating material. Ground wiring parts 7b, 7e of the wiring layers in the direction of X, Y axes are connected each other through a via hole. Power supply wiring parts 8a, 8d of the wiring layers in the direction of X, Y axes are connected each other through a via hole. Signal wiring parts 11h, 11p of the wiring layers 16, 17 in the direction of X, Y axes are connected each other through a via hole. When the ground wiring parts and the power supply wiring parts are connected in lattice, the inductance and combined resistance can be decreased even if the power supply wiring parts for the ground wiring parts and the power supply wiring parts are made narrow.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a multilayer printed wiring board.

[0002]

2. Description of the Related Art FIG. 15 shows a power supply wiring layer (power supply V) of a commonly used conventional multilayer printed wiring board (hereinafter, wiring board).
1 is a cross-sectional configuration example of an eight-layer wiring board having 1, a power source V2 (≠ V1, and including GND) and a signal wiring layer. (1) is GND
Wiring layer, (2) power source V1 wiring layer, (3) power source V2 wiring layer,
(4) is a signal wiring layer, (5) is a component mounting layer, and (48) is an insulating layer. The component mounting layer (5), the power supply V1 wiring layer (2), and G are arranged in this order from the top.
ND wiring layer (1), signal wiring layer (4), signal wiring layer (4), GN
D wiring layer (1), power supply V2 wiring layer (3), component mounting layer (5) 8
An insulating layer (48) is sandwiched between each of the layers.

FIG. 16 shows the structure of another conventional wiring board. An example of a cross-sectional structure of a six-layer wiring board having a power supply wiring layer in which two layers of a power supply wiring layer and a GND wiring layer are wired in the same layer. Is. (4) is a signal wiring layer, (5) is a component mounting layer, 2/6 layers and 5/6 layers are power feeding wiring layers, (1) is a GND wiring layer portion, and (2) is a power supply V
1 wiring layer part, (3) a power supply V2 wiring layer part, and (48) an insulating layer, in order from the top, component mounting layer (5), power supply wiring layer, signal wiring layer (4), signal wiring layer (4), a power supply wiring layer, and a component mounting layer (5), each of which is composed of six layers, and an insulating layer (48) sandwiched between the layers. The power supply wiring layer is a power source V
It consists of one wiring part and GND wiring part. The power supply wiring layer is composed of a power supply V2 wiring portion and a GND wiring portion. In the two power supply wiring layers, the power supply wiring portion and G
FIGS. 17 to 20 show specific layout examples of the ND wiring portion.

In addition to those shown in FIGS. 15 and 16, there is a conventional example shown in FIG. FIG. 17 shows Japanese Patent Laid-Open No.
It is a top view which is shown in -136567 and which shows the structural example of the electric power feeding wiring layer of a wiring board. (6) is a power supply wiring layer,
Reference numeral (7) is a GND wiring portion, and (8) is a power source V1 wiring portion which is spaced apart from the GND wiring portion (7). GND wiring section
Comb shape of (7) and this comb-shaped GND wiring part
Since one power supply wiring layer (6) is composed of the power supply V1 wiring part (8) formed in a comb shape so that the teeth of (7) mesh with each other, it is possible to reduce the number of power supply wiring layers. Next to
The number of layers of the entire wiring board can be reduced.

Another conventional example is shown in FIG. FIG. 18 is a top view showing an example of the structure of the power supply wiring layer of the wiring board disclosed in JP-A-5-136567. Reference numeral (6) is a power supply wiring layer, (7) is a GND wiring portion, and (8) is a power source V1 wiring portion which is separated from the GND wiring portion (7). GND
Since the wiring part (7) and the power source V1 wiring part (8) are adjacent to each other and parallel to each other to form one power supply wiring layer (6), it is possible to reduce the number of power supply wiring layers. The number of layers of the wiring board can be reduced.

Further, another conventional example is shown in FIG. FIG. 19 is a top view showing a configuration example of the power supply wiring layer of the wiring board disclosed in Japanese Patent Laid-Open No. 5-136567. (6) is a power supply wiring layer, (7) is a GND wiring section, and (8) is a GND wiring section
(7) is a power source V1 wiring portion which is separated from the power source by a distance.
Reference numeral (9) is a power source V2 (≠ V1) wiring portion which is separated from the GND wiring portion (7) and the power source V1 wiring portion (8) by a distance. GN
Comb-shaped D wiring part (7) and this comb-shaped GN
Power supply V1 wiring part with D wiring part (7) meshing with teeth
Composed of (8), GND wiring (7) and power supply V
Since one power supply wiring layer (6) is configured by wiring the power supply V2 wiring part (9) between the one wiring part (8), it is possible to reduce the number of power supply wiring layers, The number of layers of the entire wiring board can be reduced.

Another conventional example is shown in FIG. FIG. 20 corresponds to the one shown in Japanese Patent Laid-Open No. 5-136567, which is a countermeasure structure in which a voltage drop occurs when power is supplied from the tip portion of the comb in FIG. 17 to the element mounted on the wiring board. It is a figure which shows an example. Reference numeral (6) is a power supply wiring layer, (7) is a ground wiring portion, and (8) is a power source V1 wiring portion which is separated from the GND wiring portion (7) with a distance. GND
One power supply wiring layer (6) is formed by the comb-shaped wiring part and the comb-shaped GND wiring part (7) and the power supply V1 wiring part (8) formed so that the teeth mesh with each other. I am configuring. The power supply V1 wiring part (8f) and the power supply V1 wiring connecting VIA (10) set on a different layer from the tip of the power supply V1 wiring part (8)
It is a method of connecting physically and electrically.

Further, another conventional example is shown in FIG. FIG. 21 is an enlarged top view showing an example of a structure corresponding to that shown in Japanese Patent Laid-Open No. 6-268370, in which a signal wiring is laid in the gap between the power feeding wirings in FIGS. 17, 18, and 19. (11) is a signal wiring part, and (12) is the number of channels of the signal wiring part (11). Configuration example FIG. 17, FIG.
Since the signal wiring portion (11) having the number of channels (12) is incorporated in the gap between the power feeding wirings in FIG. 19, it is possible to reduce the number of signal wiring layers.

Still another conventional example is shown in FIG. FIG. 22 corresponds to Japanese Patent Laid-Open No. 5-136567, in which signal wiring portions that transmit signals of the same type between two signal wiring layers on a wiring board are electrically and physically connected to each other by using a signal wiring VIA. It is a figure showing an example of section composition at the time of doing. (4) is the signal wiring layer, (5) is the component mounting layer,
(1) is a ground wiring layer portion, (2) is a power supply V1 wiring layer portion, (11a) to (11f) are signal wiring portions, and (48) is an insulating layer.
A signal wiring connection VIA (20) for electrically and physically connecting the signal wiring portion (11b) and the signal wiring portion (11d) sandwiching the insulating layer is formed. ing. By connecting the signal wiring layers with the signal wiring connecting VIA, a wiring board having high wiring efficiency can be manufactured.

Another conventional example is shown in FIG. FIG. 23 shows a configuration example of a power supply wiring layer of a conventional wiring board. In FIG. 21, when the number of signal wiring portions wired between the power supply wiring portion and the GND wiring portion is one, component mounting such as IC and component mounting 3 is a top view showing the power feeding method of FIG. (13) is the component mounting layer
(5) These are IC components mounted and mounted on top. Reference numeral (14) is a GND pin connected to the GND wiring portion (7). Reference numeral (15) is a power source V1 pin of the IC component (13) connected to the power source V1 wiring section (8).
The layout of the IC component (13) is as follows: the position of the GND pin (14) of the IC component, the position of the power supply V1 pin (15), and the GND of the power supply wiring layer.
After confirming the position of the wiring part (7) and the position of the power source V1 wiring part (8), each pin is connected to each power supply line.

Further, FIG. 24 is a sectional view of FIG.
21. Configuration example of power supply wiring layer of conventional wiring board In FIG. 21, when there is one signal wiring section wired between the power supply wiring section and the GND wiring section, the method of mounting components such as IC and feeding power to the components FIG. Reference numeral (13) is an IC component mounted and mounted on the component mounting layer (5). GND wiring part (7) on the power supply wiring layer (6)
The power supply V1 wiring part (8) and the signal wiring part (9) are wired. (1
4) is a GND pin connected to the GND wiring part (7). (1
5) is the power supply V1 The power supply V of the IC component (13) connected to the wiring part (8)
1 pin. The layout of IC parts (13) is GN of IC parts.
Position of D pin (14), power source V1 pin (15), position of GND wiring part (7) of power supply wiring layer and power source V1 wiring part
Check the position of (8) and connect each pin to each power supply wiring.

[0012]

The above-mentioned conventional example has the following problems. That is, it was not possible to simultaneously perform the operation and control on each of the following elements 1 to 5. When a high-density, high-speed and high-frequency circuit is wired on a conventional wiring board, 1. Judgment as to whether or not the required number of signal wiring parts (11) can be accommodated. Control of characteristic impedance which is electric characteristic of signal wiring part (11) 3. 3. Control of crosstalk noise, which is an electrical characteristic of the signal wiring section (11). 4. Control to lower the combined resistance value, which is the electrical characteristic of the GND wiring (7) and the power supply wiring of the power supply V1 wiring (8) or the power supply V2 wiring (9). Control to lower the combined inductance value, which is the electrical characteristic of the GND wiring (7) and the power supply wiring of the power supply V1 wiring (8) or the power supply V2 wiring (9)

In order to transmit a normal signal waveform, the wiring is divided into a signal wiring layer in which only the signal wiring portion is wired as in the conventional wiring board and a power feeding wiring layer whose entire surface is a power feeding wiring portion. The wiring board is configured so as not to control the combined resistance value and the combined inductance value of each section, and the characteristic impedance, crosstalk noise, and the number of wirings of the signal wiring section regarding the signal wiring section are controlled. However, when this method is selected, there is a problem that the number of layers of the wiring board increases.

Therefore, in order to reduce the number of layers of the wiring board, a method of wiring the signal wiring portion and the power feeding wiring portion in the same layer can be considered. However, in the case of the conventional wiring board holding the comb-shaped power supply wiring layer, there is a problem that the combined resistance value and the combined inductance value of the power supply wiring section become large. To solve this problem, the method of passing the VIA to the tip of the comb to suppress the voltage drop in the power supply wiring section causes a problem that it cannot be installed unless the wiring width of the power supply wiring section is wide.

In order to wire the signal wiring portion and the power feeding wiring portion in the same layer as described above, in order to keep the combined resistance value and the combined inductance value of the feeding wiring portion low, the wiring is shown in (7) and (8) of FIG. It is necessary to widen the wiring width of the power supply wiring section. When the wiring width of the power supply wiring part is widened, when arranging parts such as IC,
Position of GND pin and power supply pin of parts, position of GND wiring part (7) of power supply wiring layer and power supply V1 wiring part (8)
Since each pin is connected to each power supply wiring after confirming the position of, the problem of spending a lot of time in arranging parts such as IC arises.

In addition to this, there is a high possibility that the place where the component can be placed is limited, or it is necessary to provide a long lead line from the component to the power supply wiring section. The limitation of the installation location of components makes high-density wiring difficult, and the laying of a long lead wire causes a problem that it is necessary to newly control the combined resistance value and the combined inductance value of the lead wire. Further, when the wiring width of the power supply wiring portion is widened, there is a problem that the total number of signal wiring portions that can be wired in one wiring layer decreases.

Example of constitution of power feeding layer of conventional wiring board Signal wiring part (11) between GND wiring part (7) and power source V1 wiring part (8) in power feeding wiring layer (6) as shown in FIG. Even when wiring is performed, it is difficult for the signal wiring portion (11) to secure the following 1 and 2 by the power feeding wiring portion between the GND wiring portion (7) and the power source V1 wiring portion (8). 1. 1. A wirable area of the signal wiring portion with respect to the signal wiring portion (11) between the GND wiring portion (7) and the power supply V1 wiring portion (8) in the power feeding wiring layer (6). Number of wiring channels (12) for each wiring layer of the signal wiring part (11) and number of wiring channels for the entire wiring board (12)

In order to increase the wirable area of the signal wiring portion (11), the GND wiring portion (7) and the power source V1 wiring portion are provided.
If the power supply wiring portion of (8) is made thin, the composite resistance value and the composite inductance value, which are the electrical characteristics of the power supply wiring, increase, which is a problem.

Furthermore, if the distance between the power supply wiring section and the GND wiring section is narrowed in order to set a large number of wiring channels (12), the value of the crosstalk noise which is the electrical characteristic of the signal wiring section (11) will be Although it can be suppressed to a low value, it becomes necessary to control the characteristic impedance between the signal wirings. In the case where the wiring channel is composed of a plurality of signal wiring portions, if the distance between the power supply wiring portion and the GND wiring portion is narrowed, the influence of crosstalk noise occurs on the transmission signal, and a normal signal waveform is not transmitted.

When the wiring channel is composed of one signal wiring portion, it is not necessary to consider the influence of crosstalk noise generated on the transmission signal regardless of the distance between the power wiring portion and the GND wiring portion. Although not provided, the number of wiring channels (12) is reduced by increasing the wiring area occupied by one signal wiring portion. Alternatively, the problem of inefficient wiring caused by the expansion of the wirable area of the power supply wiring section by wiring the power supply wiring section or the GND wiring section for each signal wiring section is encountered.

On the other hand, the GND wiring section (7) and the power source V1 wiring section
If the wiring pattern width of the (8) or the power supply V2 wiring part (9) is large, it is a problem to reduce the wirable area of the signal wiring, and at the same time, I of different power supply voltage mounted on the wiring board is used.
GN of IC parts when deciding the placement of C parts (13)
It becomes necessary to separately provide a long lead wire from the location where the D pin (14) or the power supply V1 pin (15) is arranged to the power supply wiring portion or the ground wiring portion, which causes a problem of degrading the electrical characteristics of the wiring board.

The present invention has been made in order to solve the above problems, and it is a first object of the present invention to reduce the number of layers in a conventional multilayer structure in a multilayer printed wiring board and prevent the electrical characteristics of the power supply wiring from being deteriorated. Has an aim. A second object is to obtain a multilayer printed wiring board that can reduce the influence of noise of the power supply wiring on the transmission signal.

Further, a third object is to obtain a multilayer printed wiring board which can reduce the influence of signal wiring noise on the transmission signal. A fourth object is to reduce the number of layers in the conventional multilayer structure and to install the mounted elements at a high density. A fifth object is to enable wiring of all the signal wirings in the power feeding wiring layer without installing the signal wiring layer which has been conventionally held.

[0024]

A multilayer printed wiring board according to the present invention includes a first layer having a first signal wiring portion and a first power wiring portion, a plurality of first ground wiring portions, and a first layer. A second layer having a second signal wiring section, a second power wiring section, and a plurality of second ground wiring sections connected to each of the plurality of first ground wiring sections in the first layer Is.

The multilayer printed wiring board according to the present invention comprises:
A first layer having a first signal wiring portion, a first ground wiring portion, and a plurality of first power wiring portions, a second signal wiring portion, a second ground wiring portion, and the plurality of layers in the first layer. And a second layer having a plurality of second power supply wiring parts connected to each of the first power supply wiring parts.

The first layer has a plurality of first signal wiring portions, and the second layer has a plurality of second signal wiring portions connected to each of the first signal wiring portions. Have. Further, a first layer having a first signal wiring portion between the first ground wiring portion and the first power wiring portion, and a second layer between the second ground wiring portion and the second power wiring portion. It is composed of a second layer having two signal wiring portions.

Furthermore, a first layer in which the first signal wiring portion, the first ground wiring portion, and the first power wiring portion are wired in parallel, the second signal wiring portion, and the second ground wiring. Part and the second layer in which the second power supply wiring part is wired in parallel,
Be composed. Further, the first signal wiring portion in the first layer and the second signal wiring portion in the second layer are in a twisted position.

[0028]

In the multilayer printed wiring board according to the present invention, the first layer having the first signal wiring portion, the first power wiring portion and the plurality of first ground wiring portions, the second signal wiring portion and the first signal wiring portion are provided. A second layer having a second power wiring portion and a plurality of second ground wiring portions connected to the plurality of first ground wiring portions in the first layer, and a mesh in the entire multilayer printed wiring board. The ground wiring is formed in a similar manner to reduce the inductance value and the combined resistance value of the entire ground wiring portion.

In the multilayer printed wiring board according to the present invention, the first layer having the first signal wiring portion, the first ground wiring portion and the plurality of first power wiring portions, the second signal wiring portion and the first signal wiring portion are provided. A second layer having a second ground wiring section and a plurality of second power supply wiring sections connected to each of the plurality of first power supply wiring sections in the first layer, and a mesh in the entire multilayer printed wiring board. The power supply wiring is formed in a similar manner to reduce the inductance value and combined resistance value of the entire power supply wiring portion.

Further, the first layer has a plurality of first signal wiring portions and a plurality of second signal wiring portions connected to the first signal wiring portions of the second layer, respectively. By connecting the whole board in the form of a mesh, the signal transmitted through the first signal wiring portion is connected to the second signal wiring portion without crossing the transmission wiring portion for other signals.
By passing through the IA, the direction of the signal wiring portion is changed and a signal wiring portion having a short wiring distance is realized. Further, by disposing the signal wiring portion between the power wiring portion and the ground wiring portion, the ground wiring portion or the power wiring portion blocks the magnetic field and the electric field generated from the signal wiring portion.

Furthermore, the signal wiring part and the GN on the same layer.
By wiring the D wiring portion and the power wiring portion in parallel, it becomes easy to calculate the electrical characteristics of the signal wiring portion and the power feeding wiring portion. Further, since the first signal wiring portion in the first layer and the second signal wiring portion in the second layer are in a twisted position, the first signal wiring portion and the second signal wiring portion It is possible to suppress electrostatic and magnetic field coupling between and.

[0032]

【Example】

Embodiment 1 FIG. FIG. 1 is a top view showing a wiring layer in which wiring is provided in the X-axis direction in a multilayer printed wiring board structure in an embodiment of the present invention. In addition, FIG. 2 also shows the Y orthogonal to the X axis in the multilayer printed wiring board structure in the embodiment of the present invention.
It is a top view which shows the wiring layer with which wiring was provided in the direction of an axis.
In FIG. 1, (7a) to (7c) are GND wiring parts, (8a) to (8b)
Is a power source V1 wiring portion of another potential wired in parallel with the GND wiring portions (7a) to (7c).

Reference numerals (11a) to (11h) are signal wiring portions which are wired in parallel between the GND wiring portions (7a) to (7c) and the power source V1 wiring portions (8a) to (8b). (16) is the GND wiring part (7
a) to (7c) and power supply V1 wiring section (8a) to (8b) and signal wiring section (11a)
To (11h) are wired in the X-axis direction, and the space between the wiring parts is filled with an insulating material in the X-axis direction wiring layer.

In FIG. 2, (7d) to (7e) are GND wiring portions, and (8c) to (8e) are GND wiring portions (7d) to (7e). It is a department. (11i) ~ (11p)
Are GND wiring parts (7d) to (7e) and power supply V1 wiring parts (8c) to (8e)
Is a signal wiring portion that is wired in parallel between and. (17) is a GND wiring section (7d) to (7e) and a power supply V1 wiring section on the same plane.
(8c) to (8e) and the signal wiring portions (11i) to (11p) are wired in the Y-axis direction, and a wiring layer between the wiring portions is filled with an insulating material in the Y-axis direction.

FIG. 3 shows the X-axis direction wiring layer (16) as the first wiring layer and the Y-axis direction wiring layer as the second wiring layer.
FIG. 16 is a connection top view of different-direction wiring layers in which an insulating material is sandwiched between (17) and both layers and laminated. (18) is a wiring layer in the X-axis direction (16)
GND wiring parts (7a) to (7c) and the Y-axis direction wiring layer (17)
G to physically and electrically connect D wiring parts (7d) to (7e)
It is a VIA for ND wiring connection.

(19) is a power supply V1 wiring section (8a) to (8b) of the X-axis direction wiring layer (16) and a power supply V1 wiring section (8) of the Y-axis direction wiring layer (17).
c) to (8e) is a VIA for connecting a power source V1 wiring physically and electrically. (20) is a signal wiring portion (11a) to (11h) of the X-axis direction wiring layer (16) and a signal wiring portion of the Y-axis direction wiring layer (17)
(11i) to (11p) is a signal wiring connection VIA that physically and electrically connects signal wiring portions that transmit the same type of signal.

FIG. 4 is a top view of the connection between different-direction wiring layers in which the X-axis direction wiring layer and the Y-axis direction wiring layer are laminated.
FIG. 6 is a connection cross-sectional view between different-direction wiring layers showing a cross section when the upper part is cut along a dashed line AB. The ground wiring portion (7e), the power supply wiring portion (8d), and the signal wiring portion (11p) of the Y-axis wiring layer (17) can be seen in the upper layer of the connection cross-sectional view between different-direction wiring layers. Further, in the lower layer of the connection cross-sectional view, ground wiring portions (7a) to (7c), power wiring portions (8a) to (8b), and signal wiring portions (11a) to (of the X-axis direction wiring layer (16) are provided. 11h) can be seen.

Further, the ground wiring portion (7e) of the Y-axis wiring layer
The ground wiring connection VIA (18) that physically and electrically connects between the wiring and the ground wiring portion (7b) of the wiring layer in the X-axis direction.
And a power supply wiring connection VIA (19) that physically and electrically connects the power supply wiring part (8d) of the Y-axis wiring layer and the power supply wiring part (8a) of the X-axis direction wiring layer. A signal wiring connection VIA (20) that physically and electrically connects the signal wiring portion (11p) of the Y-axis wiring layer and the signal wiring portion (11h) of the X-axis direction wiring layer that transmits signals of various types. ) Can be seen.

The wiring structure of the multilayer printed wiring board of this embodiment will be described with reference to FIGS. In FIG. 1, in the X-axis direction wiring layer (16), the GND wiring portions (7a) to (7c) and the power source V1
The wiring portions (8a) to (8b) are wired with the same wiring width and in a straight line and in parallel, the ground wiring portions and the power supply wiring portions are alternately arranged, and the ground wiring portions and the power supply wiring portions are arranged at a constant interval.
Also, the signal wiring parts (11a) to (11h) are connected to the GND wiring part and the power source V
Wire 2 wires between each wire.

By wiring all of the ground wiring portion, the power supply wiring portion, and the signal wiring portion in a straight line and in parallel, the wiring design of each wiring portion becomes easy. Also, by placing the signal wiring section between the ground wiring section and the power supply wiring section of the power supply wiring section, a shielding effect can be expected, and stable signal transmission with less noise that suppresses crosstalk noise in the signal wiring section is performed. be able to.

Furthermore, by arranging two signal wiring portions between the power feeding wiring portions, it is possible to suppress variations in the characteristic impedance value of the signal wiring portions. By stabilizing the characteristic impedance value of the signal wiring portion, it is possible to suppress the occurrence of reflection noise and to perform stable signal transmission. Furthermore, it is possible to suppress the variation in the characteristic impedance value of the signal wiring portion by wiring the signal wiring portions one by one between the power feeding wiring portions,
By arranging two signal wiring parts between the power supply wiring part and the GND wiring part, the total number of signal wiring parts that can be wired on the entire wiring board can be significantly increased.

In FIG. 2, in the Y-axis direction wiring layer (17),
The GND wiring parts (7d) to (7e) and the power supply V1 wiring parts (8c) to (8e) have the same wiring width and are straight and parallel, and the ground wiring part and the power supply wiring part are alternated and the ground wiring part And the wiring between the power supply and the power supply are constant. In addition, the signal wiring part (11
Two lines i) to (11p) are provided between the GND wiring portion and the power source V1 wiring portion.

By wiring all of the ground wiring portion, the power supply wiring portion, and the signal wiring portion in a straight line and in parallel, the wiring design of each wiring portion becomes easy. Also, by placing the signal wiring section between the ground wiring section and the power supply wiring section of the power supply wiring section, a shielding effect can be expected, and stable signal transmission with less noise that suppresses crosstalk noise in the signal wiring section is performed. be able to.

Furthermore, by arranging two signal wiring portions between the power feeding wiring portions, it is possible to suppress variations in the characteristic impedance value of the signal wiring portions. By stabilizing the characteristic impedance value of the signal wiring portion, it is possible to suppress the occurrence of reflection noise and to perform stable signal transmission. Furthermore, it is possible to suppress the variation in the characteristic impedance value of the signal wiring portion by wiring the signal wiring portions one by one between the power feeding wiring portions,
By arranging two signal wiring parts between the power supply wiring part and the GND wiring part, the total number of signal wiring parts that can be wired on the entire wiring board can be significantly increased.

In FIG. 3, an X-axis direction wiring layer and a Y-axis direction wiring layer having different wiring directions by 90 degrees are laminated with an insulating material sandwiched between the two layers. The ground wiring portion in the X-axis direction wiring layer and the ground wiring portion in the Y-axis direction wiring layer are physically and electrically connected using VIA at all points. The VIA is used to physically and electrically connect the power supply wiring portion in the X-axis direction wiring layer and the power supply wiring portion in the Y-axis direction wiring layer at all the points closest to each other.
Further, among the points where the signal wiring portion in the X-axis direction wiring layer and the signal wiring portion in the Y-axis direction wiring layer are closest to each other, the signal wiring portions that transmit the same type of signal are physically and electrically connected by VIA. To do.

X for the ground wiring section and the power supply wiring section
VI between the axial wiring layer and the Y-axis wiring layer is arranged in a grid pattern.
Physically and electrically connected using A. Then, even if the wiring width of the power supply wiring portion such as the ground wiring portion or the power supply wiring portion is narrowed, the combined inductance value and the combined resistance value can be suppressed to be low. Since it is possible to suppress the combined inductance value and the combined resistance value of the power supply wiring portion to be low, it is possible to suppress the voltage drop in the power supply wiring portion due to the combined inductance value and the combined resistance value. By narrowing the wiring width of the power supply wiring section to reduce the area occupied by the power supply wiring section in the wiring layer, the area of the signal wiring section occupied in the wiring layer is increased. As a result, it becomes possible to manufacture a thin multilayer printed wiring board in which the total number of wiring layers in the wiring board is reduced without providing a single signal wiring layer in the wiring board.

Further, by using the VIA for the signal wiring portion to form the signal wiring portion in a three-dimensional structure, wiring can be performed without being influenced by the wiring directions of other signal wiring portions. Further, the X-axis direction wiring layer and the Y-axis direction wiring layer are 9
By wiring the wiring parts in directions different from each other by 0 degree, X
It is possible to perform stable signal transmission between the signal wiring portion of the axial wiring layer and the signal wiring portion of the Y-axis wiring layer without being affected by crosstalk noise.

The following seven points are concrete examples of connection points using the signal wiring connection VIA in FIG. 1. The point where the signal wiring part (11h) on the X-axis direction wiring layer (16) and the signal wiring part (11p) on the Y-axis wiring layer (17) come closest to each other. 2. The point where the signal wiring part (11d) on the X-axis direction wiring layer (16) and the signal wiring part (11p) on the Y-axis wiring layer (17) come closest to each other. 3. The point where the signal wiring part (11a) on the X-axis direction wiring layer (16) and the signal wiring part (11l) on the Y-axis wiring layer (17) are closest to each other. 4. The point where the signal wiring portion (11g) on the X-axis wiring layer (16) and the signal wiring portion (11l) on the Y-axis wiring layer (17) come closest to each other. 5. The point where the signal wiring portion (11b) on the X-axis wiring layer (16) and the signal wiring portion (11k) on the Y-axis wiring layer (17) come closest to each other. 6. The point where the signal wiring portion (11h) on the X-axis wiring layer (16) and the signal wiring portion (11k) on the Y-axis wiring layer (17) come closest to each other. 7. The point where the signal wiring part (11c) on the X-axis direction wiring layer (16) and the signal wiring part (11i) on the Y-axis wiring layer (17) come closest to each other.

FIG. 4 is a sectional view of the top view of FIG. 3 taken along the line AB. In the top view of FIG. 3, the ground wiring portions (7a to 7c) in the X-axis direction wiring layer and the Y-axis direction are shown. The ground wiring portions (7d, 7e) in the wiring layer are in a positional relationship of twisting by 90 degrees, and the distance between the ground wiring portion of the X-axis direction wiring layer and the ground wiring portion of the Y-axis direction wiring layer is closest. Physically and electrically connect all points with VIA.

In the top view of FIG. 3, the power supply wiring portions (8a, 8b) in the X-axis direction wiring layer and the power supply wiring portions (8c to 8e) in the Y-axis direction wiring layer are twisted by 90 degrees. In relation to the power wiring portion of the wiring layer in the X-axis direction and the Y wiring portion.
All points where the distance between the axial wiring layer and the power supply wiring portion is closest are physically and electrically connected by VIA.

Further, in the top view of FIG. 3, the signal wiring portions (11a to 11h) in the X-axis direction wiring layer and the signal wiring portions (11i to 11p) in the Y-axis direction wiring layer are twisted by 90 degrees. In VIA, all the points having the closest distance between the two wiring portions between the signal wiring portion of the X-axis direction wiring layer and the signal wiring portion of the Y-axis direction wiring layer that have the same relationship and transmit the same type of signal are VIA. Connect physically and electrically.

FIG. 5 is a flow chart showing a procedure for selecting the structure of each wiring portion on the multilayer printed wiring board according to the present invention. The multilayer printed wiring board designed based on this flowchart satisfies the following 14 conditions.

1. 2 of X-axis direction wiring layer and Y-axis direction wiring layer
It is composed of layers. 2. The X-axis direction wiring layer and the Y-axis wiring layer are composed of a GND wiring portion, a power supply wiring portion and a signal wiring portion. 3. The GND wiring portion, the power supply wiring portion, and the signal wiring portion are parallel to each other. 4. Two signal wiring portions are wired between the GND wiring portion and the power supply wiring portion. 5. The GND wiring portion in the X-axis direction wiring layer and the Y wiring portion
There is a 90-degree twisted positional relationship with the GND wiring portion in the axial wiring layer. 6. The GND wiring portion in the X-axis direction wiring layer and the Y wiring portion
All points at which the two wiring portions of the GND wiring portion in the axial wiring layer are closest to each other are physically and electrically connected by VIA. 7. The power source wiring portion in the X-axis direction wiring layer and the power source wiring portion in the Y-axis direction wiring layer are in a positional relationship of twisting by 90 degrees. 8. VIA is used to physically and electrically connect all points where the two wiring portions of the power wiring portion in the X-axis wiring layer and the power wiring portion in the Y-axis wiring layer are closest to each other. 9. The signal wiring portion in the X-axis direction wiring layer and the signal wiring portion in the Y-axis direction wiring layer are in a positional relationship of twisting by 90 degrees. 10. All points closest to each other between the power supply wiring portion in the X-axis direction wiring layer and the power supply wiring portion in the Y-axis direction wiring layer that transmit the same type of signal are physically and electrically connected by VIA. 11. The GND wiring part and the power supply wiring part have the same wiring pattern width. 12. The GND wiring portion and the power supply wiring portion are wired alternately. 13. The distance between the GND wiring portion and the power supply wiring portion is constant. 14． The interval between the GND wiring part or the power supply wiring part and the signal wiring part is constant.

The processing contents of FIG. 5 will be described in order based on the above 14 preconditions. In step 51, a plurality of analysis parameter groups having the following five parameters as one analysis parameter group are input. 1. Wiring pattern width of signal wiring part 2. 2. The wiring pattern width of the ground wiring part and the power supply wiring part that use the same input value. 3. Distance between signal wiring part and power feeding wiring part 4. Distance between signal wiring section and signal wiring section The number of wirings of the signal wiring portion to be wired between the ground wiring portion and the power supply wiring portion in the wiring layer shown in FIG. 1 or 2.

Step 60 is a step of judging the combined inductance value of the power supply wirings, and the combined inductance value of the power supply wirings in the wiring layer wired by the input data falls within the target combined inductance value of the power supply wirings. It is determined whether or not, and the input data of step 52 is used for the input data reaching the target. Step 80 is a determination processing step for the combined resistance value of the power supply wiring, and it is determined whether the combined resistance value of the power supply wiring in the wiring layer wired by the input data is within the target combined resistance value of the power supply wiring. The input data which is determined and reaches the target is the input data of step 52.

Step 90 is a determination processing step regarding the wiring permission rate of the signal wiring, and the wiring permission rate of the signal wiring in the wiring layer wired by the input data falls within the target wiring permission rate of the signal wiring. It is determined whether or not, and the input data of step 52 is used for the input data reaching the target. Step 110 is a determination processing step regarding the characteristic impedance of the signal wiring, and it is determined whether the characteristic impedance of the power feeding wiring in the wiring layer wired by the input data is within the target characteristic impedance of the power feeding wiring, The input data of step 52 is applied to the input data reaching the target.

Step 140 is a determination process for the crosstalk noise value of the signal wire, and the crosstalk noise value of the power wire in the wiring layer wired by the input data is the target crosstalk noise value of the power wire. If the input data reaches the target, it becomes the input data of step 52. Step 5
2 selects an analysis parameter group that satisfies all of the above five determination items from the input analysis parameter group selected from the above five determination processing steps. In step 53, the result obtained in step 52 is output.

FIG. 6 is a design flow chart for selecting an input analysis parameter group such that the target combined inductance value of the power supply wiring section falls within the allowable range. In step 51, a plurality of analysis parameter groups having the following five parameters as one analysis parameter group are input. 1. Wiring pattern width of signal wiring part 2. 2. The wiring pattern width of the ground wiring part and the power supply wiring part that use the same input value. 3. Distance between signal wiring part and power feeding wiring part 4. Distance between signal wiring section and signal wiring section The number of wirings of the signal wiring portion to be wired between the ground wiring portion and the power supply wiring portion in the wiring layer shown in FIG. 1 or 2.

In step 61, when mounting an element such as an IC on a wiring board, a judgment reference value based on the value of the package inductance of the element is input so that the noise source can be limited to the element. In step 62, two constants, that is, the magnetic permeability of the insulating layer and the thickness of the power supply wiring portion are input and set. In step 63, the order i of the analysis parameter groups to be processed is compared with the total number x of the input analysis parameter groups, and the order i becomes larger than the total number x, and whether all the input analysis parameter groups have been processed. I'm making a decision. If all the analysis parameter groups have been processed, step 52, step 60, step 80, step 90, step 110, and step 140.
The process proceeds to the common analysis parameter group selection processing step satisfying the above five conditions. If the determination process has not been performed for all the analysis parameter groups, the process proceeds to step 64.

In step 64, the combined inductance value Lvia of the power supply wiring portion when the wiring board is constructed based on a certain analysis parameter group in the input analysis parameter group is calculated. In step 65, the combined inductance value Lvia of the power feeding wiring part when the wiring board is configured based on the certain analysis parameter group calculated in step 64 is the step 6
It is determined whether or not the value is suppressed below the determination reference value set in 1. At this time, if the combined inductance value Lvia of the power supply wiring portion calculated in step 64 is suppressed below the judgment reference value set in step 61, the process proceeds to step 66 and then to step 67. On the contrary, if the combined inductance value Lvia of the power supply wiring portion calculated in step 64 is not suppressed below the judgment reference value set in step 61, the process proceeds to step 67 without proceeding to step 66.

In step 66, the analysis parameter group used in step 64, which is derived from the combined inductance value of the power supply wiring portion to be determined at the time of determination in step 65, is one of the candidates for determining the sectional shape of the wiring layer. Save as. The analysis parameter group stored and stored in step 52 is step 60, step 80, and step 90.
In step 67 of selecting whether or not the analysis parameter group is a common analysis parameter group satisfying the five conditions of step 110 and step 140, the order i of the analysis parameter group to be processed is incremented to the next order.

In step 61 of FIG. 6, a value is input as if the combined inductance value Lvia of the power supply wiring layer should be less than y percent of the inductance value Lpin of the package, and Lpin + (y / 100) Lpin is set. Use as the judgment reference value. Further, in the judgment of step 65, it is judged whether or not the value of Lpin + Lvia is smaller than the value of Lpin + (y / 100) Lpin set in step 61. In addition, VI
The ideal relationship between the inductance Lvia between A and the parasitic inductance Lpin of the element is Lvia = Lpin = 0.

By suppressing the voltage fluctuation due to the inductance value of the power supply wiring section, the influence of noise on the transmission signal is suppressed.

FIG. 7 is a sectional view of a wiring layer of a wiring board showing an embodiment of the present invention. In FIG. 7, (7) is a GND wiring portion, and (8) is a power source V1 wiring portion. (11) is the GND wiring part
In the signal wiring section that connects between (7) and the power supply V1 wiring section (8),
(27) is the number n of signal wiring lines of the signal wiring portion (11). (21) is a GND wiring part (7), a power supply V1 wiring part (8), and a signal wiring part
It is the conductor thickness t of (11). (22) is a power supply wiring width Wg of the GND wiring portion (7) and the power source V1 wiring portion (8), and (23) is a signal wiring portion.
It is the signal wiring width WS of (11). Reference numeral (24) is a power-signal gap Ggs between the GND wiring portion (7) or the power source V1 wiring portion (8) and the signal wiring portion (11). (25) is a signal-signal gap Gss between the signal wiring portion (11) and another signal wiring portion (11). (26) is an insulating material having a relative dielectric constant εr.

FIG. 8 is a design flow chart for selecting an input analysis parameter group such that the target combined inductance value of the power supply wiring section falls within the allowable range. In step 51, a plurality of analysis parameter groups having the following five parameters as one analysis parameter group are input. 1. Wiring pattern width of signal wiring part 2. 2. The wiring pattern width of the ground wiring part and the power supply wiring part that use the same input value. 3. Distance between signal wiring part and power feeding wiring part 4. Distance between signal wiring section and signal wiring section The number of wirings of the signal wiring portion to be wired between the ground wiring portion and the power supply wiring portion in the wiring layer shown in FIG. 1 or 2.

In step 81, a judgment reference value based on the power supply voltage value of the element is input in order to suppress noise caused by the voltage drop in the power supply wiring section. In step 82, two constants of the specific resistance of the power supply wiring and the thickness of the power supply wiring portion are input and set. In step 83, the order i of the analysis parameter group to be processed is compared with the total number x of the input analysis parameter groups, and the order i becomes larger than the total number x, and whether all the input analysis parameter groups have been processed. I'm making a decision. If all the analysis parameter groups have been processed, step 52, step 60, step 80, and step 90
Then, the process proceeds to the common analysis parameter group selection processing step satisfying the five conditions of step 110 and step 140.
If the determination process has not been performed for all analysis parameter groups, the process proceeds to step 84.

In step 84, the combined resistance value R of the power supply wiring portion when the wiring board is constructed based on a certain analysis parameter group in the inputted analysis parameter group is calculated. In step 85, it is checked whether the combined resistance value R of the power feeding wiring part when the wiring board is configured based on the certain analysis parameter group calculated in step 84 is suppressed to be equal to or less than the determination reference value set in step 81. judge. At this time, if the combined resistance value R of the power supply wiring portion calculated in step 84 is suppressed to be equal to or less than the determination reference value set in step 81, the process proceeds to step 86 and then to step 87. On the contrary, when the combined resistance value R of the power supply wiring portion calculated in step 84 is not suppressed to be equal to or lower than the determination reference value set in step 81, the process proceeds to step 87 without proceeding to step 86.

At step 86, the analysis parameter group used at step 84, which is derived from the combined resistance value of the power supply wiring portion to be determined at the time of determination at step 85, is one of the candidates for determining the sectional shape of the wiring layer. Save as. In step 52, the stored analysis parameter group is subjected to a selection process to determine whether it is a common analysis parameter group satisfying the five conditions of step 60, step 80, step 90, step 110, and step 140.
Then, the order i of the analysis parameter group to be processed is incremented in the next order.

In step 81 of FIG. 8 described above, the combined resistance value R of the power supply wiring layer is the power supply voltage E of the mounted element, the allowable voltage drop rate e (%) of E, and the most current between certain adjacent VIAs. The determination reference value is Ee / I calculated from the current amount I when flowing. Further, in the determination of step 85, it is determined whether or not the value of R is smaller than the Ee / I set in step 81.

By suppressing the voltage drop amount due to the combined resistance value of the power supply wiring portion, noise to the transmission signal is suppressed.

FIG. 9 is a design flowchart for selecting an input analysis parameter group so that the target wiring possibility ratio of the signal wiring portion falls within the allowable range. FIG.
Reference numeral 0 denotes a cross-sectional shape of a wiring layer which is formed only of the signal wiring portion (11) without the GND wiring portion (7) and the power supply wiring portion of the power source V1 wiring portion (8) in the same layer. From FIGS. 7 and 10, it is possible to calculate the ratio of the signal wiring portion to the total area of one wiring layer with and without the power feeding wiring portion of the GND wiring portion (7) and the power supply V1 wiring portion (8). This ratio is defined as the wiring possibility ratio.

The wiring possibility ratio r (0 <r <1) can be calculated by the following formula. r = n × (GSS + WS) / {WG + 2 × GGS + (n-1)
XGSS + nxWS} From this, it is possible to determine whether the wiring accommodating capacity is sufficient in the case of the sectional configuration of FIG. The flow chart of the design for performing the above processing is as follows.

At step 51, a plurality of analysis parameter groups having the following five parameters as one analysis parameter group are input. 1. Wiring pattern width of signal wiring part 2. 2. The wiring pattern width of the ground wiring part and the power supply wiring part that use the same input value. 3. Distance between signal wiring part and power feeding wiring part 4. Distance between signal wiring section and signal wiring section The number of wirings of the signal wiring portion to be wired between the ground wiring portion and the power supply wiring portion in the wiring layer shown in FIG. 1 or 2.

In step 91, a higher wirable rate is input and set so that all the required signal wiring portions can be laid and the extra signal wiring portions are not laid as much as possible. In step 92, the order i of the analysis parameter group to be processed is compared with the total number x of the input analysis parameter groups, and the order i becomes larger than the total number x, and whether all the input analysis parameter groups have been processed. I'm making a decision.

If all the analysis parameter groups have been processed, a common analysis parameter group satisfying the five conditions of step 60, step 80, step 90, step 110 and step 140 of step 52 is selected. Go to processing step. If the determination process has not been performed for all the analysis parameter groups, the process proceeds to step 93. In step 93, the wiring possibility ratio r of the signal wiring portion when the wiring board is configured is calculated based on a certain analysis parameter group in the inputted analysis parameter group.

In step 94, the wirable rate r of the signal wiring portion when the wiring board is constructed based on the certain analysis parameter group calculated in step 93 is suppressed to the wirable rate set in step 91 or less. Determine whether or not At this time, when the wiring possibility ratio r of the signal wiring portion calculated in step 93 is suppressed to be equal to or lower than the wiring possibility ratio set in step 91, the routine proceeds to step 95 and then to step 96. On the contrary, if the wiring possibility ratio r of the signal wiring portion calculated in step 93 is not suppressed below the wiring possibility ratio set in step 91, the process proceeds to step 96 without proceeding to step 95.

In step 95, the analysis parameter group used in step 93, which is derived from the wiring possibility of the signal wiring portion to be judged at the time of judgment in step 94, is one of the candidates for determining the sectional shape of the wiring layer. Save as. In step 52, the stored and saved analysis parameter group is subjected to selection processing to determine whether it is a common analysis parameter group satisfying the five conditions of step 60, step 80, step 90, step 110, and step 140.
Then, the order i of the analysis parameter group to be processed is incremented in the next order.

FIG. 10 shows a cross-sectional shape of a wiring layer which is composed of only the signal wiring portion (11) without the GND wiring portion (7) and the power supply wiring portion of the power source V1 wiring portion (8) in the same layer. (11) is the signal wiring portion, (21) is the thickness of each signal wiring portion, (23) is the wiring width of the signal wiring portion, (25) is the width between the signal wiring portions, and (26) is each signal wiring portion. It is the magnetic permeability in vacuum of the insulating layer filling the gap.

FIG. 11 is a design flowchart for selecting an input analysis parameter group such that the target characteristic impedance of the signal wiring portion falls within the allowable range. In step 51, a plurality of analysis parameter groups having the following five parameters as one analysis parameter group are input. 1. Wiring pattern width of signal wiring part 2. 2. The wiring pattern width of the ground wiring part and the power supply wiring part that use the same input value. 3. Distance between signal wiring part and power feeding wiring part 4. Distance between signal wiring section and signal wiring section The number of wirings of the signal wiring portion to be wired between the ground wiring portion and the power supply wiring portion in the wiring layer shown in FIG. 1 or 2.

In step 111, the range of the characteristic impedance value is empirically determined in order to suppress the reflection noise generated from the variation of the characteristic impedance of the signal wiring portion, and then the judgment reference value for the variation difference of the characteristic impedance is input. To do. At step 112, two constants of the magnetic permeability of the insulating layer and the thickness of the power supply wiring portion are input and set. In step 113, the order i of the analysis parameter group to be processed is compared with the total number x of the input analysis parameter groups, and the order i becomes larger than the total number x, and whether all the input analysis parameter groups have been processed. I'm making a decision.

If all the analysis parameter groups have been processed, a common analysis parameter group satisfying the five conditions of step 52, step 60, step 80, step 90, step 110, and step 140 is selected. Go to processing step. If the determination process has not been performed for all the analysis parameter groups, the process proceeds to step 114.

In step 114, the characteristic impedance of the signal wiring portion when the wiring board is constructed based on a certain analysis parameter group in the input analysis parameter group is calculated. In step 115, it is determined whether or not the characteristic impedance of the signal wiring portion when the wiring board is configured based on the certain analysis parameter group calculated in step 114 is suppressed below the determination reference value set in step 111. .

At this time, if the characteristic impedance of the signal wiring portion calculated in step 114 is suppressed below the judgment reference value set in step 111, the process proceeds to step 116. On the contrary, when the characteristic impedance of the signal wiring portion calculated in step 114 is not suppressed to be equal to or lower than the determination reference value set in step 111, the process proceeds to step 118 without proceeding to step 116. In step 116, the characteristic impedance of the signal wiring portion when the wiring board is configured based on the analysis parameter group calculated in step 114 and satisfying the determination criterion in step 115 is less than or equal to the determination criterion value set in step 111. It is determined whether or not it is suppressed to.

At this time, the characteristic impedance of the signal wiring portion when the wiring board is constructed based on the analysis parameter group calculated in step 114 and satisfying the criterion in step 115 is the criterion set in step 111. If it is suppressed below the value, the routine proceeds to step 117.
On the contrary, it is calculated in step 114, and step 11
If the characteristic impedance of the signal wiring portion when the wiring board is configured based on the analysis parameter group that satisfies the judgment criterion of 5 is not suppressed below the judgment criterion value set in step 111, proceed to step 117. No, the process proceeds to step 118.

In step 117, step 114 in which the characteristic impedance of the signal wiring portion to be judged is derived in the two judgments of step 115 and step 116.
The analysis parameter group used in step 1 is stored and saved as one of the candidates that can determine the cross-sectional shape of the wiring layer. The analysis parameter group stored and stored in step 52 is a common analysis parameter group satisfying the five conditions of step 60, step 80, step 90, step 110, and step 140. In step 118, the analysis parameter to be processed is selected. The parameter group order i is incremented in order.

In FIG. 11, the relationship between the feed-signal gap Ggs (24) and the signal-signal gap Gss (25) is calculated as Ggs = Gss, but the feed-signal gap Ggs (24) is calculated. And the signal-signal gap Gss (25) are set to different intervals, each is calculated as a separate parameter, and the best interval feed-signal gap Ggs (24) and signal-signal gap Gss (25) are calculated. ) Is determined.

FIG. 12 shows the GND wiring part (7) shown in FIG.
1 to 9 (n = 1 to 9) of the signal wiring number n (27) of the signal wiring portion (11) for wiring between the power feeding wiring portion of the power source V1 wiring portion (8) and In this case, the variation range of the characteristic impedance data of each signal wiring part (11) is shown. For example, when the number of signal wires n (27) of the signal wire portion (11) is 6, the variation range of the characteristic impedance of the 6 wires is about 20Ω. Than this,
The allowable range of the characteristic impedance is compared and judged to determine the allowable wiring channel number n of the signal wiring section (11).

FIG. 13 shows the signal wiring portion shown in FIG.
When the number of signal wires n (27) in (11) is two, the feed-signal gap GGS (24) and the signal-signal gap GSS (25) change in the range of 20 to 120 μm. 5 is a graph showing the variation range of the characteristic impedance of FIG. Feed-signal gap Ggs (24) and signal-signal gap Gss that achieve the characteristic impedance allowable range (27)
Decide (25).

FIG. 14 is a design flowchart for selecting an input analysis parameter group so that the target crosstalk noise amount of the signal wiring portion falls within the allowable range. In step 51, a plurality of analysis parameter groups having the following five parameters as one analysis parameter group are input. 1. Wiring pattern width of signal wiring part 2. 2. The wiring pattern width of the ground wiring part and the power supply wiring part that use the same input value. 3. Distance between signal wiring part and power feeding wiring part 4. Distance between signal wiring section and signal wiring section The number of wirings of the signal wiring portion to be wired between the ground wiring portion and the power supply wiring portion in the wiring layer shown in FIG. 1 or 2.

In step 141, in order to suppress the noise to the transmission signal by suppressing the amount of crosstalk noise between the signal wiring portions, the voltage amplitude value of the noise source, the device rise time and the device fall time are set. The allowable saturation voltage of the crosstalk noise, which is set by input and calculated from the above three parameters, is used as the determination reference value.

At step 142, two constants, that is, the magnetic permeability of the insulating layer and the thickness of the power supply wiring portion are input and set. Step 1
In 43, the order i of the analysis parameter group to be processed is i.
And the total number x of input analysis parameter groups are compared with each other, and it is determined whether or not the order i becomes larger than the total number x and all the input analysis parameter groups have been processed.

If all the analysis parameter groups have been processed, a common analysis parameter group satisfying the five conditions of step 52, step 60, step 80, step 90, step 110 and step 140 is selected. Go to processing step. If the determination process has not been performed for all the analysis parameter groups, the process proceeds to step 144.

In step 144, the amount of crosstalk noise in the signal wiring portion when the wiring board is configured based on a certain analysis parameter group in the input analysis parameter group is calculated. In step 145, it is checked whether the crosstalk noise amount of the signal wiring portion when the wiring board is configured based on the certain analysis parameter group calculated in step 144 is suppressed to be equal to or less than the determination reference value set in step 141. judge.

At this time, if the crosstalk noise amount of the signal wiring portion calculated in step 144 is suppressed to be equal to or less than the determination reference value set in step 141, the process proceeds to step 146 and then to step 147. On the contrary, if the amount of crosstalk noise in the signal wiring portion calculated in step 144 is not suppressed to be equal to or smaller than the determination reference value set in step 141, the process proceeds to step 147 without proceeding to step 146.

At step 146, at the time of the determination at step 145, the analysis parameter group used at step 144, which has derived the crosstalk noise amount of the signal wiring portion to be determined, is used as a candidate for determining the cross-sectional shape of the wiring layer. Save as one. At step 147, the analysis parameter group stored and saved is subjected to a process of selecting whether it is a common analysis parameter group satisfying the five conditions of step 60, step 80, step 90, step 110, and step 140. The parameter group order i is incremented in order.

Conventionally, the above-described five elements of the composite inductance value of the power supply wiring, the composite resistance value of the power supply wiring, the wiring tolerance of the signal wiring, the characteristic impedance of the signal wiring, and the crosstalk noise of the signal wiring are sufficiently satisfied. Although a multi-layer printed wiring board with properties was not made,
The product of the present invention is a multilayer printed wiring board capable of sufficiently satisfying the above five elements. In this conventional example, the first layer is the X-axis direction wiring layer and the second layer is the Y-axis direction wiring layer, but the reverse is also true.

[0097]

Since the present invention is constructed as described above, it has the following effects. A first layer having a first signal wiring portion, a plurality of first ground wiring portions and a first power wiring portion, and a plurality of the first grounds in the second signal wiring portion and the first layer Since it is composed of a second layer having a plurality of second ground wiring portions and a second power wiring portion connected to each of the wiring portions, the signal wiring portion, the ground wiring portion, and the power wiring portion are the same. By having one layer, the total number of wiring layers can be reduced.

Further, since the combined inductance value and the combined resistance value can be controlled to be low even if the wiring width of the ground wiring portion is narrowed, high density arrangement of elements such as ICs becomes possible. Further, since the combined inductance value and the combined resistance value of the ground wiring portion can be controlled to be low, it is possible to suppress the voltage fluctuation and suppress the noise to the transmission signal.

A first layer having a first signal wiring portion, a first ground wiring portion, and a plurality of first power wiring portions, a second signal wiring portion, a second ground wiring portion, and a first layer. A second wiring having a plurality of second power supply wiring portions connected to each of the plurality of first power supply wiring portions in the layer, so that the signal wiring portion, the ground wiring portion, and the power wiring By having parts in the same layer, it is possible to reduce the total number of wiring layers.

Further, since the combined inductance value and combined resistance value can be controlled to be low even if the wiring width of the power supply wiring portion is narrowed, high density arrangement of elements such as ICs becomes possible. Further, since the combined inductance value and combined resistance value of the power supply wiring section can be controlled to be low, it is possible to suppress the voltage fluctuation and suppress the noise with respect to the transmission signal.

The first layer has a plurality of first signal wiring portions, and the second layer has a plurality of second signal wiring portions connected to each of the first signal wiring portions. Therefore, at an intersection that occurs when the shortest wiring is performed on the same wiring layer with a certain signal wiring portion and a different signal wiring portion,
By moving one wiring portion to another layer, crossing can be easily avoided, and the wiring distance can be shortened easily.

Further, the first layer having one or two first signal wiring portions between the first ground wiring portion and the first power wiring portion, the second ground wiring portion and the second layer. Since it is composed of the second layer having one or two second signal wiring portions between the power wiring portion and the power wiring portion, it depends on the characteristic impedance of the signal wiring portion due to the shielding effect of the ground wiring portion and the power wiring portion. Noise can be suppressed.

Furthermore, the first signal wiring portion, the first ground wiring portion, and the first power wiring portion are wired in parallel, the first signal wiring portion, the second signal wiring portion, and the second ground wiring portion. Part and the second layer in which the second power supply wiring part is wired in parallel,
Since it is configured, it can be easily designed and manufactured at the stage of commercialization.

Further, since the first signal wiring portion in the first layer and the second signal wiring portion in the second layer are in a twisted position, there is a difference between the two signal wiring portions. It is possible to control the influence of crosstalk noise generated by electromagnetic coupling and electrostatic coupling.

[Brief description of the drawings]

FIG. 1 is a top view showing an X-axis direction wiring layer in a wiring board structure in an example.

FIG. 2 is a top view showing a Y-axis direction wiring layer in a wiring board structure in an example.

3 is a top view of the connection between different-direction wiring layers in which the X-axis direction wiring layer and the Y-axis direction wiring layer of FIG. 1 in the example are laminated.

FIG. 4 is a cross-sectional view of the wiring board structure of FIG.
It is the sectional view seen from B.

FIG. 5 is a flowchart of a cross-section structure determination process based on various electrical characteristics in the example.

FIG. 6 is a flowchart of a process of narrowing down a sectional structure from an inductance in the example.

FIG. 7 is a cross-sectional view showing a wiring layer configuration in an example.

FIG. 8 is a flowchart of a narrowing-down process of a sectional structure based on a combined resistance value in the example.

FIG. 9 is a flowchart of a process of narrowing down a cross-sectional structure based on the wirable ratio in the example.

FIG. 10 is a cross-sectional view showing a wiring layer configuration when a ground wiring portion and a power supply wiring portion are not held.

FIG. 11 is a flowchart of a narrowing-down process of a sectional structure based on characteristic impedance in the example.

FIG. 12 is a graph showing the relationship between the number of signal wirings sandwiched between the GND wiring and the power supply wiring of the wiring board structure and the characteristic impedance of the signal wiring in the example.

FIG. 13 is a graph showing the relationship between the number (1 to 9) of signal wirings sandwiched between the GND wiring and the power supply wiring of the wiring board structure and the characteristic impedance of the signal wiring at intervals.

FIG. 14 is a flowchart of a cross-sectional structure narrowing-down process based on crosstalk noise in the example.

FIG. 15 is a cross-sectional view of a conventional eight-layer wiring board structure.

FIG. 16 is a cross-sectional view of a conventional six-layer wiring board structure.

17 is a top view of the power supply wiring layer at the time of comb wiring in the power supply wiring layer of FIG.

FIG. 18 is a top view of the power supply wiring layer at the time of parallel wiring in the power supply wiring layer of FIG. 16;

FIG. 19 further includes a different power supply for the power supply wiring layer of FIG.
FIG. 7 is a top view of the power supply wiring layer when comb-shaped wiring is performed after adding types.

20 is a top view of the power supply wiring layer in which a voltage drop countermeasure is taken by connecting the tip portions of the combs with VIA in order to suppress the voltage drop of the power supply wiring layer in FIG. 17;

FIG. 21 is a top view of a power supply wiring layer in which a signal wiring portion is provided between a ground wiring portion and a power wiring portion in the conventional technique.

FIG. 22 is a cross-sectional view of a wiring board in which signal wiring portions wired in different wiring layers according to a conventional technique are interconnected using VIA.

FIG. 23 is a top view of a power supply wiring layer showing a problem regarding arrangement of elements in a conventional wiring board structure.

FIG. 24 is a cross-sectional view of a power supply wiring layer showing a problem regarding arrangement of elements in a wiring board structure of a conventional technique.

[Explanation of symbols]

 1 GND wiring layer 2 Power supply V1 wiring layer 3 Power supply V2 wiring layer 4 Signal wiring layer 5 Component mounting layer 6 Power supply wiring layer 7, 7a to 7e GND wiring portion 8, 8a to 8f Power supply V1 wiring portion 9 Power supply V2 wiring portion 10 Connection VIA 11, 11a to 11p Signal wiring part 12 Number of channels 13 IC parts 14 GND pin 15 Power supply V1 pin 16 X-axis direction wiring layer 17 Y-axis direction wiring layer 18 GND wiring connection VIA 19 Power supply V1 wiring connection VIA 20 signal VIA for wiring connection 21 Conductor thickness t 22 Feeding wiring width Wg 23 Signal wiring width Ws 24 Feeding-signal gap Ggs 25 Signal-signal gap Gss 26 Insulation material 27 Number of signal wirings n 48 Insulation layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Mamoru Ogura 5-11 1-1 Ofuna, Kamakura-shi, Kanagawa Mitsubishi Electric Corporation, Information Systems Research Laboratory (72) Tetsuo Motomiya 1-1, Miyashita, Sagamihara-shi, Kanagawa No. 57 Sanryo Electric Co., Ltd. Printed circuit board factory

Claims (6)

[Claims] 1. A first layer having a first signal wiring portion, a first power wiring portion, and a plurality of first ground wiring portions, a second signal wiring portion, a second power wiring portion, and a first layer. A multilayer printed wiring board comprising: a second layer having a plurality of second ground wiring portions connected to each of the plurality of first ground wiring portions in a single layer and laminated on a first layer. 2. A first layer having a first signal wiring portion, a first ground wiring portion, and a plurality of first power wiring portions, a second signal wiring portion, a second ground wiring portion, and a first layer. A multilayer printed wiring board comprising: a second layer having a plurality of second power supply wiring parts connected to each of the plurality of first power supply wiring parts in a single layer and laminated on a first layer. 3. The first layer has a plurality of first signal wiring portions, and the second layer has a plurality of second signal wiring portions connected to each of the first signal wiring portions. The multilayer printed wiring board according to claim 1 or 2, wherein. 4. A first layer having a first signal wiring portion between a first ground wiring portion and a first power wiring portion, a second ground wiring portion and a second power wiring portion. The multilayer printed wiring board according to claim 1 or 2, wherein the multilayer printed wiring board comprises a second layer having a second signal wiring portion therebetween. 5. A first layer in which a first signal wiring portion, a first ground wiring portion, and a first power wiring portion are wired in parallel,
The multilayer printed wiring board according to claim 1 or 2, wherein the second signal wiring portion, the second ground wiring portion, and the second power wiring portion are constituted by a second layer in which the second wiring is arranged in parallel. 6. The multilayer printed wiring board according to claim 5, wherein the first signal wiring portion on the first layer and the second signal wiring portion on the second layer are in a twisted position.