JPH0577198B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a printed wiring board that requires parallel patterns, such as a backboard board, and particularly to a printed wiring board that reduces guidance between patterns.

[Background of the Invention] Printed wiring boards are used not only to mount various electronic and electrical components in the construction of electronic and electrical devices, but also to interconnect boards mounted with such components. An example is shown in Figure 2. Note that such a connection board is called a backboard board, and in Fig. 2, this backboard board is represented by 1, 2 represents the terminal of the connector, 3 represents the wiring pattern, and 4 represents the circuit board. .

Backboard board (hereinafter referred to as BB board) 1
Although not shown in the figure, a plurality of multi-pole connectors are attached to the circuit board 4, and the terminals 2 are connected to each other by the wiring pattern 3. There are a plurality of terminals 2 corresponding to each pole of the multi-pole connector, and the terminals 2 constitute a plurality of terminal groups as a whole, and these plurality of terminals 2 are arranged in a straight line as shown in the figure. It goes without saying that various components are mounted on the circuit board 4 as required.

By the way, such a mounting method using the BB board 1 is relatively widely used in various control devices, etc., but in such devices, the terminals 2 of the multi-pole connector are arranged in a regular manner for each circuit board 4. In many cases, the wiring patterns 3 are connected parallel to each other, so that most of the wiring patterns 3 are parallel patterns.

FIG. 3 shows an example of such a conventional BB board 1, and in the figure, a1 to an, b1 to bn, c
1 to cn are through holes for connecting connector terminals 2 (FIG. 2), and 3a, 3b, . . . , 3x are conductor strip patterns constituting the wiring pattern 3. Among the conductor strip patterns, the strip pattern 3a connects all the through holes a1 corresponding to the terminals of each connector, and the strip pattern 3b connects all the through holes c1. Similarly, other strip patterns 3c~
3x are through holes a2 to an and c2 respectively
As a result, the wiring pattern 3 becomes a parallel pattern, and as is clear from the conductor strip patterns 3b and 3c, the spacing between the conductor strip patterns is the same as that of the topmost one. All of them, except for the one at the bottom, have two through holes, making them quite narrow, and the width of the strips has to be made quite narrow as well.

Therefore, conventional BB boards and the like have the disadvantage that it is difficult to lower the impedance of the wiring pattern and that they are easily affected by induced noise. This problem has become an even bigger problem due to higher density packaging and higher speed circuit elements.

On the other hand, an example of a method that provides some sort of solution to the problem of induced noise is the proposal in Japanese Patent Application Laid-Open No. 129386/1986, but this proposed method does not require through-holes. There are problems such as the need for a large number of patterns, which may increase the cost, and the number of patterns for the back conductor layer, which may result in insufficient area for a portion useful for shielding.

[Purpose of the invention]

The purpose of the present invention is to eliminate the drawbacks of the prior art described above, to sufficiently suppress induced noise even when a parallel pattern is formed on a BB substrate, etc., and to be able to sufficiently cope with higher density and higher speed. To provide low cost and printed wiring boards.

[Summary of the invention]

In order to achieve this object, the present invention is characterized in that every other conductor strip pattern that should be a parallel pattern is taken out, the wiring pattern is divided into two groups, and these are used as patterns for different routes. .

[Embodiments of the invention]

EMBODIMENT OF THE INVENTION Hereinafter, the printed wiring board according to the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 shows one embodiment of the present invention, and the BB substrate 1, through holes a1-an, b1-bn, c1-cn, and conductor strip patterns 3a, 3c, 3e-3x, etc. are the conventional example shown in FIG. is the same as In this FIG. 1, 5a, 5b, 5c..., 6a,
6b, 6c... are conductor strip patterns, s1, s
2, s3... are through holes.

Note that in this embodiment, the strip conductor pattern 3a
~3x is called the first group of strip conductor patterns, 5a to 5c are the second group of strip conductor patterns,
In addition, 6a to 6c are called detour conductor strip patterns.

In addition, in this example, as described later, BB
A substrate 1 having two conductor layers on the front and back sides,
A so-called double-sided substrate is used, and the first group of striped conductor patterns 3a to 3x and the second group of striped conductor patterns 5a to 5c have a surface conductor layer (first
The detour conductor strip patterns 6a to 6c are formed by the conductor layer (second conductor layer) on the back side.
It is formed by

The conductor strip patterns 5a, 5b, 5c... are through holes a1~an, b1~bn, c1~ provided corresponding to the terminals 2 of the respective multipolar connectors.
It is formed in the space below the cn,
It is connected to the conductor strip patterns 6a, 6b, 6c, . . . by through holes s2, s4, s6, .

The conductor strip patterns 6a, 6b, 6c... are
Conductor strip patterns 3a, 3c, 3e on BB board 1
〜3x and a surface different from the surface on which 5a, 5b, 5c... are formed (for example, the back surface compared to the front surface)
are formed in the upper through holes s1, s3, s
5... and the lower through holes s2, s4, s6...
It is formed to connect...

The upper through holes s1, s3, s5... are
Among the through holes provided corresponding to the terminals of each connector, conductive strip patterns 6a, 6b, 6c...
It functions to connect...

As a result, among the through holes provided corresponding to the terminals of each connector, predetermined ones of the through holes c1 to cn arranged side by side on the right side of the figure are connected to the conductor strip pattern 6a, 6b, 6c
. . . and 5a, 5b, 5c, . . . .

On the other hand, the through holes a1 to an corresponding to the terminals of each connector are as in the case of the conventional example shown in FIG.
Conductor strip pattern 3 in parallel pattern
They are directly connected to each other by a, 3c, 3e to 3x.

Therefore, according to this embodiment, every other predetermined conductor strip pattern is sequentially taken out of a plurality of parallel conductor strip patterns for connecting the terminals of each connector. The spacing between each conductor strip pattern of the parallel wiring patterns is 2 times larger than that of the conventional example.
The conductor portion can be made into a wider pattern, suppressing the increase in impedance, and reducing induced noise.

In the above embodiments, a so-called double-sided board having a conductor layer on the front and back sides was used as the BB board 1, but the present invention is not limited to this, and can be applied to a so-called multilayer board having three or more conductor layers. Needless to say, it is still possible to implement it.

Furthermore, it goes without saying that the present invention is applicable not only to BB boards but also to any printed wiring boards having parallel patterns.

〔Effect of the invention〕

As explained above, according to the present invention, the spacing between the parallel conductor strip patterns can be sufficiently widened, thereby eliminating the drawbacks of the prior art and making it possible to cope with higher density and higher speed. A low-cost printed wiring board that can sufficiently reduce induced noise even when applied to backboards, improve electrical characteristics and reliability, and improve manufacturing yield. can be easily provided.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of a printed wiring board according to the present invention, FIG. 2 is a perspective view showing an example of a backboard board, and FIG. 3 is a front view showing a conventional example of a printed wiring board. 1...Backboard board, 2...Multi-pole connector terminal, 3...Wiring pattern, 4...Circuit board,
3a, 3c, 3e-3x, 5a, 5b, 5c, 6
a, 6b, 6c...conductor strip pattern, a1~
an, b1~bn, c1~cn...Through holes for multi-pole connector terminals, s1~s6...Through holes.

Claims (1)

[Claims] 1. A wiring pattern consisting of a plurality of conductor strips arranged in parallel connects corresponding terminals of a plurality of connection terminal groups consisting of a plurality of terminals arranged perpendicularly to these wiring patterns. In the printed wiring boards connected in parallel to each other, a wiring board having at least two conductor layers, a first and a second layer, is used, and
At least a portion of the conductor strips are sequentially divided into first and second groups, and the first and second groups of conductor strips are respectively connected to the wiring board by the first conductor layer. formed at different locations, the first group of conductor strips being directly connected to the terminals;
A printed wiring board characterized in that said second group of strip conductors is configured to be connected to said terminal via a detour conductor strip formed by said second conductor layer. 2. The printed wiring board according to claim 1, wherein the connection terminal group has at least two terminal rows each consisting of a plurality of linearly arranged terminals.