JPS60127798A - Multilayer printed circuit board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides at least one power supply/ground layer for mounting electronic components and electrically connecting the components;
The present invention relates to a multilayer printed wiring board having two or more layers including at least one signal layer.

Prior Art Conventionally, in the multilayer printed wiring board of this building, the first
As shown in FIGS. 2 and 3, the wiring channels 3 in the Y direction and the wiring channels 4 in the The examples shown in FIGS. 1, 2, and 3 have one, two, and three wiring channels, respectively.

Here, in the example of FIG. 3 having three wiring channels 3 and 4 between the signal through-holes 2, a fifth diagram showing an example where three wiring patterns 41, 42, 43 are applied in the X direction. The plan view (a) of the figure and its -A-A sectional view (b)
), the power supply/ground layer 7 on the lower surface is provided with a clearance 5 excluding the copper foil of the conductor layer in the portion in contact with the signal through hole 2 to avoid short circuit with the signal layer.

Therefore, the wiring pattern of signal layer 1 is 41°42.43
Of these, the wiring patterns 41 and 43 that pass close to the clearance 5 of the power/ground layer 7 have a higher characteristic impedance than the wiring pattern 42 that does not pass over the clearance 5. That is, there is a drawback that the characteristic impedance of wiring patterns in the same layer differs depending on the wiring channel through which the pattern passes.

OBJECTS OF THE INVENTION An object of the present invention is to reduce the width of a wiring pattern that passes through a position close to the signal through hole among the wiring patterns forming a wiring channel, which is a route through which signal layer wiring is possible. It is an object of the present invention to provide a multilayer printed wiring board that solves the above-mentioned drawbacks by forming a width larger than that of a wiring pattern that passes through a position further away from the wiring pattern.

Structure of the Invention In order to achieve the above-mentioned object, the present invention has two layers including at least one power supply/ground layer and at least one signal layer, and having a series of many signal through holes on the entire surface.
In a multilayer printed wiring board with more than one layer, the width of the wiring pattern that passes through a position close to the signal through hole is determined by the width of the wiring pattern that forms a wiring channel that is a route through which the signal layer can be routed. This configuration employs a configuration in which the width of the wiring pattern is larger than that of the wiring pattern that passes through a position further away from the wiring pattern.

Example Next, the present invention will be described by way of examples with reference to the drawings.

In FIG. 6 showing the first embodiment of the present invention, the two-layer printed wiring board of the present invention has a signal layer 1 and a power supply/ground layer 7 stacked with an insulating layer in between.

It has a series of many signal through holes 2.

The signal layer 1 is an example of wiring when three wiring channels are set as shown in FIG. 3, and three wiring patterns 9.
10.11, and the lower power supply/ground layer 7 is provided with a clearance 5 around the signal through hole 2 to avoid short circuit with the signal layer.

The wiring patterns 9 and 11 pass over part of the clearance 5 of the power supply/ground layer 7, and the wiring nozzle 10 does not pass over this clearance 5. Therefore, in order to avoid an increase in the characteristic impedance of the wiring patterns 9 and 11 that pass over the clearance 5, the pattern width of the wiring patterns 9 and 11 is made larger than the width of the wiring pattern 10 to lower the characteristic impedance. This is intended to reduce fluctuations in characteristic impedance and to reduce variations in characteristic impedance depending on location within one signal layer.

Next, in the second embodiment of the present invention, two wiring patterns 12 are arranged in the X direction of the wiring channel corresponding to the conventional wiring channel shown in FIG.
．． This is a two-layer printed wiring board having a wiring pattern 13, whose plan view is shown in FIG.
．． 13 has a different distance from the signal through hole 2,
The wiring pattern 12 does not pass over the clearance 5, but the wiring pattern 13 does pass over the clearance 5.

Therefore, the width of the wiring pattern 13 is increased to lower its characteristic impedance, and the characteristic impedances of both are matched.

Due to this K, it is possible to reduce the variation in characteristic impedance depending on the location within one signal layer, as in the first embodiment.

Note that although the above embodiments have been described with respect to a two-layer printed wiring board consisting of two layers, a signal layer and a power supply/ground layer, a multilayer printed wiring board that includes these two layers or has a plurality of these two layers laminated can also be used. It is clear that variations in the characteristic impedance of the wiring patterns of each signal layer can be slightly reduced in the same way.

Therefore, there is no electrical mismatch in the signal transmission system within the multilayer printed circuit board of the present invention, which has the effect of reducing loss.

As described in detail, according to the present invention, a configuration is adopted in which the pattern width can be used depending on the wiring channel, and as follows, variations in the characteristic impedance of each wiring pattern and variations in characteristic impedance depending on the location within one signal layer can be reduced. It can be made smaller, eliminate electrical mismatch, and reduce loss in the signal transmission thread.

[Brief explanation of the drawing]

1, 2, 3, and 4 show examples of conventional wiring channels in plan view.
In this book, Figures 2 and 4 are two between the signal through holes, and one between the third
The figure shows three wiring channels between signal through holes.
FIG. 5 is a plan view (a) of an example of three wiring patterns between signal through-holes in the prior art and a cross-sectional view (b) taken along the line A-A.
), FIG. 6 is a plan view of the first embodiment of the present invention, and FIG. 7 is a plan view of the second embodiment of the present invention. 1°”°°゛Signal layer of multilayer printed wiring board, 2...
... Signal through hole, 3... Wiring channel in the Y direction, 4... Wiring channel A in the X direction,
5...Clearance in power supply/ground layer, 6...Land of signal through hole, 7°°
°°゛Power supply φ grapher power layer ground...Insulating layer, 9,
10.11,12,13゜41.42.43°°゛°・
Wiring pattern in the °X direction. i, -,,,:-nij Fan S Gui

Claims (1)

[Claims] In a multilayer printed wiring board with two or more layers, including at least one power supply/ground layer and at least one signal layer, and having a series of many signal through holes on the entire surface, a route that can be routed on layer No. 48 Among the wiring patterns forming a wiring channel, the width of the wiring pattern passing through a position close to the signal through hole is p larger than the width of the wiring pattern passing through a position farther from the signal through hole. A multilayer printed wiring board characterized in that: 1