JPH0946009A - Wiring board electronic device wherein it is used - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain spurious radiation from a power supply wiring by arranging a plane-like ground wiring and a plane-like power supply wiring so that electric line of force generated between both wirings cancels each other. SOLUTION: A printed board 10 is a multilaytered printed board, and a signal wiring 30, an electric supply wiring 40 and ground wirings 51, 52 are therein. The power supply wiring 40 and the ground wirings 51, 52 from what is called a solid pattern having a plane shape spreading all over a board. Since a power supply voltage is applied between the power supply wiring 40 and a ground wiring 51 or 52, electric lines of force 71, 72 are generated. Here, the power supply wirting 40 and the ground wirings 51, 52 have the same configuration and are arranged to overlap mutually up and down. A distance between a power supply wiring and a ground wiring and a distance between a power supply wiring and a ground wiring are made the same. Since electric lines of force 71, 72 in to directions have the same size and direction thereof are different 180 deg., they cancel each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing an electronic device, and more particularly to an electronic device having a structure for suppressing unnecessary electromagnetic radiation.

[0002]

2. Description of the Related Art Electronic devices continue to advance at higher speeds and larger scales, and there is no end to them. With the rapid operation of electronic devices, many processes and complicated processes can be easily used, and with large scale, many convenient and useful functions are realized, and electronic devices are useful to more people in the world. Contributing to the development of the electronic industry.

As electronic devices operate at high speed and become large in scale,
Generates unwanted electromagnetic radiation.

When an electronic device produces unwanted electromagnetic radiation,
It is important to design and manufacture an electronic device in which electromagnetic radiation is unlikely to occur, because a problem may occur in the operation of other electronic devices. For this reason, regulations regarding electromagnetic radiation are provided.

Further, when the electronic device operates at high speed, there is a property that unnecessary electromagnetic radiation increases, and when the electronic device becomes large-scale, unnecessary electromagnetic radiation occurs due to an increase in current consumption and the number of wirings. Tends to increase.

[0006] Therefore, the problem of unnecessary electromagnetic radiation becomes more and more important with the progress of high-speed operation and large scale of electronic devices.

Conventionally, techniques for dealing with this unnecessary electromagnetic radiation have been developed. The most widely known method is to shield electronic devices.

[0008] This typical method is a technique in which the electronic circuit is surrounded in all directions by a shield case made of a ground conductor.
According to this technique, basically, all the electromagnetic radiation waves emitted from the electronic circuit can be prevented from going out to the outside world.

An example of the prior art can be found in Japanese Utility Model Laid-Open No. 5-59897. This technique is shown in FIG. In the figure, the shield case parts 91, 92, 93 are made of metal plates, and are a shield case lid, a shield case side plate, and a shield case bottom plate, respectively, and these three members constitute a shield case. Surround all directions. That is, this technique uses a technique in which the entire circumference of the electronic circuit is surrounded by a shield case composed of a ground conductor, and the present invention is that the shield case is devised in terms of assembling.

In addition, there is a technique of using a cabinet or housing of an electronic device as a shield case made of a ground conductor, and this technique also can prevent electromagnetic radiation waves emitted from an internal electronic circuit from going out to the outside.

Another form of the prior art is a technique of shielding a printed circuit board. Most of the unnecessary electromagnetic radiation is generated from the wiring inside the printed circuit board, so the technique of shielding the printed circuit board is effective.

An example of this prior art is the actual Kaihei 5-102693.
It can be found in Japanese Utility Model Publication No. 5-243782 and Japanese Utility Model Publication No. 6-52191.

In Japanese Utility Model Laid-Open No. 5-102693 and Japanese Utility Model Laid-Open No. 5-243782, as shown in FIGS. 14 and 15, planar ground wirings 47 and 4 are formed above and below the signal wiring 33 in the printed circuit board.
8 are arranged, and these ground wirings are electrically connected by the through holes 62, and have a structure in which unnecessary electromagnetic radiation from the signal wiring is shielded and suppressed. In particular, in Japanese Utility Model Laid-Open No. 5-243782, as shown in FIG. 14, a conductive hole for conducting the upper and lower ground layers is formed on both sides of the signal wiring, and the circumference x of the signal wiring is formed in all directions by the ground conductor. By forming a structure that roughly surrounds it, a high shielding effect is realized.

[0014]

However, if the electronic device further advances in operation speed and scale, it may happen that the conventional technique is not sufficient.

In recent years, more and more electronic devices perform non-stop operation, and in this case, new technology is required. In a non-stop operation electronic device, generally, when a part fails, the failed part is maintained or replaced while the operation of the electronic device is continued. That is,
At the time of maintenance or replacement work, the cabinet or housing is opened while the operation of the electronic device is continued.
At this time, the cabinet or the case does not serve as a shield. Therefore, it is necessary that the electromagnetic radiation amount of the internal electronic circuit itself is equal to or less than the regulation value.

It may be unfavorable for economical or other reasons to use a material or structure having a high shielding effect for the cabinet or housing, and the amount of electromagnetic radiation of the internal electronic circuit itself may be below the regulated value. May be required.

Here, it is technically possible to house the individual electronic circuits inside in a shield case, but in terms of cost,
Alternatively, there is a problem that the device becomes large in size, which is difficult to implement.

There are techniques for reducing unnecessary electromagnetic radiation of individual electronic circuits, which are easy to implement, in the prior art, specifically, Japanese Utility Model Publication No. 5-102693 and Japanese Utility Model Publication No. 5-243782. , These are all aimed at reducing unnecessary electromagnetic radiation from the signal wiring, and are not technologies for reducing unnecessary electromagnetic radiation from the power wiring system, that is, the system consisting of the power wiring and the ground wiring. , Not all unwanted electromagnetic radiation can be reduced.

Therefore, if the electronic device further increases in speed and scale, the conventional technology may not be sufficient, and in particular, unnecessary electromagnetic radiation from the power supply wiring system of each electronic circuit may occur. Technology to reduce is needed.

As an example in which unnecessary electromagnetic radiation is generated from the power supply wiring system in each electronic circuit, there is a structure shown in FIG. This is an example of a printed circuit board. This printed circuit board has a planar power supply wiring 50 and a planar ground wiring 4 inside.
Has zero. Between the two wirings, a change in the current consumption due to the operation of the electronic circuit causes a change in the voltage, which causes a change in the electric field or the electric force line 70. Leaks out of the printed circuit board, causing unnecessary electromagnetic radiation. This phenomenon similarly occurs not only on the printed circuit board but also on various laminated wiring boards such as ceramic wiring boards and thin film wiring boards. Hereinafter, the ground wiring and the power wiring will be collectively referred to as a power wiring system.

As the electronic device further increases in operation speed and scale, a technique for suppressing unnecessary electromagnetic radiation from such power supply wiring is required.

[0022]

In order to solve the above technical problems, the present invention appropriately arranges the ground wiring and the power wiring for the unnecessary electromagnetic radiation generated from the ground wiring and the power wiring of the wiring board.

According to one aspect of the present invention, a plurality of sets of ground layers and power supply layers facing each other are provided as a layer structure of a wiring board.
Place these sets appropriately.

According to another aspect of the present invention, the wiring for the power supply and the ground in the wiring board is formed by a combination of linear patterns,
These patterns are arranged alternately with each other.

[0025]

According to the present invention, by appropriately arranging the power supply wiring and the ground wiring in the wiring board, the lines of electric force generated between the two wirings are canceled to reduce unnecessary electromagnetic radiation generated from the power supply wiring system. can do.

[0026]

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

FIG. 1 shows an overall view of an electronic device according to a first embodiment of the present invention. In FIG. 1, a power source 01, a printed board 11, a backboard 12, and the like are housed in a housing, and an electronic circuit element 20 is mounted on the printed board 11.
Note that, in the same figure, the case and others are omitted from the drawing.

FIG. 2 is a sectional view of the printed circuit board according to the first embodiment of the present invention. The printed circuit board 10 is a multi-layer printed circuit board, in which there are a signal wiring layer, a power supply wiring layer, and a ground wiring layer. The signal wiring 30, the power wiring 40, and the ground wiring 5 are provided.
There are 1,52. The printed circuit board has through holes 60 for electrically connecting different layers. An electronic component 20 is mounted on the surface of the substrate. The power supply wiring 40 and the ground wirings 51 and 52 have a surface shape that spreads over the entire substrate.
This is a so-called solid pattern. In this solid pattern,
Holes for through holes, holes for screws, etc. are shown as needed. In addition, there is a through hole for connection that electrically connects the two ground wiring layers.

Since a power supply voltage is applied between the signal wiring 40 and the ground wiring 51 or 52, electric fields or lines of electric force 71, 72 are generated. Since there are two ground lines, the generated lines of electric force are the two lines of electric force lines 71 from the power supply line 40 to the ground line 51 and the electric line of force 72 from the power line 40 to the ground line 52. appear. The electric lines of force in these two directions differ in direction by 180 degrees.

Here, the power supply wiring 40 and the ground wiring 51,
52 has the same shape and is arranged so as to exactly overlap with each other. Further, the distance between the power supply wiring and the ground wiring is the same as the distance between the power supply wiring and the ground wiring. Therefore, the electric force lines or electric fields in the two directions described above have the same magnitude.

The electric lines of force 71 and 72 in the two directions have the same size, and the directions thereof are different by 180 degrees, which cancel each other.
Therefore, unnecessary electromagnetic radiation from the power supply wiring and the ground wiring of the printed circuit board, that is, the power supply wiring system is suppressed. In reality, components that do not cancel out remain due to subtle differences in the shapes of the power supply wiring and ground wiring patterns, misalignment in layout, and inconsistencies in spacing, but this is unnecessary from the power supply wiring system of this printed circuit board. Such electromagnetic radiation can be easily reduced to 1/10 or less as compared with the case where the technique according to the present invention is not used.

FIG. 3 is a sectional view of a printed circuit board according to the second embodiment of the present invention. The structure of the printed circuit board of this embodiment is similar to that of the first embodiment shown in FIG. 3, except that the signal wiring 30 is provided between the power supply wiring 40 and the ground wiring 51 or 52. There is. The lines of electric force 71 and 72 generated on the printed circuit board of the second embodiment have the same size and the directions thereof are different by 180 degrees, and therefore cancel each other out. The unnecessary electromagnetic radiation from the power supply wiring system of the printed circuit board can be easily reduced to 1/10 or less as compared with the case where the technique according to the present invention is not used.

FIG. 4 is a sectional view of a printed circuit board according to the third embodiment of the present invention. In the figure, the power supply wiring is planar and 41 and 4
There are two sheets of No. 2 and two ground wirings of 51 and 52.
Electric force lines 7 generated on the printed circuit board of the third embodiment
Since 1 and 72 have the same size and are different in direction by 180 degrees, they cancel each other. Unwanted electromagnetic radiation from the power supply wiring system of the printed circuit board is easily reduced to 1/10 or less as compared with the case where the technique of the present invention is not used.

FIG. 5 shows a sectional view of a printed circuit board according to a fourth embodiment of the present invention. In the figure, the power supply wiring is planar and 41 and 4
There are two sheets of No. 2 and three ground wirings 51, 52 and 53 in a plane. The lines of electric force generated on the printed circuit board of the fourth embodiment are 71 and 73 facing downward, 72 and 74 facing upward, and the directions of both groups are 180 degrees lake. Also, select the layout of the power supply wiring and the ground wiring, and
The sum of the sizes of 1 and 73 and the sum of the sizes of the lines of electric force 72 and 74 are set to be the same. Therefore, the lines of electric force generated on this printed circuit board cancel out as a whole.
The unnecessary electromagnetic radiation from the power supply wiring system of the printed circuit board can be easily reduced to 1/10 or less as compared with the case where the technique according to the present invention is not used.

FIG. 6 shows a perspective view of a multi-chip module (hereinafter abbreviated as MCM) which is a fifth embodiment of the present invention. In the figure, a ceramic substrate 11 which is a multilayer wiring substrate.
The electronic component 20 is mounted on the ceramic substrate 11, and the ceramic substrate 11 has pins 80 on the lower surface. The MCM is mounted on a larger printed circuit board, and the connection between the MCM and the printed circuit board is made via the pin 80. The ceramic substrate 11 has signal wiring, power wiring, and ground wiring inside.

FIG. 7 shows the ceramic substrate of this MCM.
The structure of the power supply wiring and the ground wiring is shown. Both the power supply wiring and the ground wiring are formed in a thin and long pattern,
In the same layer, they are arranged in parallel, and the patterns of the ground wiring and the patterns of the power supply wiring are alternately arranged. The arrangement direction of the pattern is different by 90 degrees between different layers.
That is, the power supply wirings 45 and the ground wirings 55 are arranged in parallel and alternately, and the power supply wirings 45 and 46 and the ground wirings 55 and 56 are different in pattern arrangement direction by 90 degrees. Further, the patterns of the ground wiring and the patterns of the power wiring are electrically connected to each other through a through hole 61. In this way, the ground wiring pattern and the power supply wiring pattern are alternately arranged and at the same time, each of them forms a substantially solid shape.

FIG. 8 shows the cross section of the wiring and the state of the lines of electric force in the cross section of the ceramic substrate. In the figure, lines of electric force 75 and 76 are generated between the lines adjacent to each other on the left and right, but since the directions are different by 180 degrees and the distance between lines is the same, the lines of electric force are the same. The lines of electric force adjacent to are canceled out. Downward electric lines of force 77 are generated in the vertically adjacent wirings, but there is no electric line of force in the opposite direction in FIG.

FIG. 9 shows another cross section of the wiring in the cross section of the ceramic substrate and the state of the lines of electric force. In the figure, the lines of electric force 7
8 is upward, is 180 degrees opposite to the electric force tip 77 of FIG. 8, and has the same size, so the electric force tip 77 and the electric force line 78 cancel each other.

Therefore, the lines of electric force in the ceramic substrate cancel out as a whole, and the unnecessary electromagnetic radiation from the power supply wiring system of the ceramic substrate is 1/10 as compared with the case where the technique according to the present invention is not used. Reduced to:

FIG. 10 shows a sectional view of a ceramic substrate according to the sixth embodiment of the present invention. The structure of the figure is similar to that of the fifth embodiment shown in FIG. 9 and only the number of layers is increased. Therefore, the lines of electric force in this ceramic substrate cancel each other out, and the power supply wiring system of this ceramic substrate is canceled. Unnecessary electromagnetic radiation from the, compared to the case without using the technology according to the present invention,
It is reduced to 1/10 or less.

FIG. 11 is a sectional view of a printed board according to the seventh embodiment of the present invention. This structure is one in which the structure of the power supply wiring and the ground wiring shown in FIG. 7 is implemented on a printed board, and like the fifth and sixth embodiments, the lines of electric force on this printed board are generally Unwanted electromagnetic radiation from the power supply wiring system of this ceramic substrate is canceled to 1/10 or less as compared with the case where the technique according to the present invention is not used.

FIG. 12 shows the structure of the power supply wiring and the ground wiring in the ceramic substrate of the sixth embodiment of the present invention. In the figure, the power supply wirings 45 and the ground wirings 55 are arranged in parallel and alternately, and the power supply wirings 45 and 46 and the ground wirings 55 and 56 are different in the pattern arrangement direction by 90 degrees. This situation is the same as in the fifth embodiment shown in FIG. However, the signal wiring 32 is arranged between the power supply wiring 45 and the ground wiring 55 or between the power supply wiring 46 and the ground wiring 56. With such a structure, the signal wiring can be formed in the ceramic substrate without providing a layer dedicated to the signal wiring, and the number of layers of the ceramic substrate can be reduced. Also, in this structure, since there is a ground wiring or a power wiring between the signal wiring,
Generation of crosstalk noise between signal lines can be suppressed to a low level.

The electric lines of force between the power supply wiring and the ground wiring in this ceramic substrate cancel out as a whole, as in the fifth embodiment, and unnecessary electromagnetic radiation from the power supply wiring system of this ceramic substrate is conventionally It is reduced to 1/10 or less compared with.

The materials, dimensions and the like in the embodiments should be appropriately selected in designing individual products, and do not affect the essence or the effect of the present invention. For example, the technique of the present invention can be applied to electronic devices using a thin film wiring board, silicon wiring, etc. in addition to the electronic devices to be printed boards and ceramic substrates mentioned in the embodiments, and the conductor of the wiring is made of metal. However, other shapes can be used, and the shapes of wirings and through holes can be other sizes and shapes depending on the process and material used.
It is possible to use the present invention as a part of an electronic device, but these do not affect the essence of the present invention or the presence or absence of effects.

[0045]

According to the present invention, unnecessary electromagnetic radiation from the wiring-based power supply wiring system can be reduced to 1/10 or less as compared with the case where the technique of the present invention is not used. That is, the present invention has an effect of reducing unnecessary electromagnetic radiation from the power supply wiring system of the wiring base to 1/10 or less of the conventional technique.

Therefore, with the use of the technique of the present invention, it is necessary to open the cabinet or housing of the electronic device for operation, or to use a material or structure having a high shielding effect for the cabinet or housing of the electronic device. In the case, or, if you do not want to adopt a shield case in the electronic circuit inside the electronic device, suppress the electromagnetic radiation amount of the electronic circuit itself inside the electronic device below the regulation value, therefore,
It is possible to suppress the amount of electromagnetic radiation of the electronic device to the regulation value or less.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an example of a printed circuit board according to the present invention.

FIG. 3 is an explanatory diagram showing an embodiment of a printed circuit board according to the present invention.

FIG. 4 is an explanatory diagram showing an embodiment of a printed circuit board according to the present invention.

FIG. 5 is an explanatory view showing an embodiment of the printed circuit board of the present invention.

FIG. 6 is an explanatory diagram showing a fifth embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a structure of a ground power supply wiring according to a second embodiment of the present invention.

FIG. 8 is an explanatory view showing an embodiment of the ceramic substrate of the present invention.

FIG. 9 is an explanatory diagram showing an embodiment of the ceramic substrate of the present invention.

FIG. 10 is an explanatory view showing an embodiment of the ceramic substrate of the present invention.

FIG. 11 is an explanatory view showing an embodiment of the printed circuit board of the present invention.

FIG. 12 is an explanatory diagram showing the structure of the ground power supply wiring according to the second embodiment of the present invention.

FIG. 13 is an explanatory diagram showing a conventional technique.

FIG. 14 is an explanatory diagram showing a conventional technique.

FIG. 15 is an explanatory diagram showing a conventional technique.

FIG. 16 is an explanatory diagram showing a conventional technique.

[Explanation of symbols]

 30 ... Signal wiring, 40 ... Power wiring, 51, 52 ... Ground wiring, 71, 72 ... Electric force lines.

Claims (6)

[Claims] 1. A wiring board comprising a conductor layer formed on a dielectric layer and a plurality of laminated conductor layers, wherein a planar ground wiring is provided.
A planar power supply wire is provided, and the arrangement of the planar ground wire and the planar power supply wire cancels each other by lines of electric force generated between the planar ground wire and the planar power supply wire. A wiring board characterized by being arranged in the following manner. 2. An electronic device having the wiring board according to claim 1. 3. A wiring board comprising a conductor layer formed on a dielectric counter layer, and a plurality of such conductor layers being laminated or not laminated, wherein a plurality of linear ground wirings and a linear power supply wiring are provided. A wiring board having a plurality of wires, and the linear ground wiring and the linear power wiring are arranged in parallel and alternately. 4. The wiring board according to claim 3, wherein a signal wiring is provided between the linear ground wiring and the linear power wiring. 5. An electronic device having the wiring board according to claim 3. 6. An electronic device having the wiring board according to claim 4.