JPH04326600A - Clay-like shielding material - Google Patents

Abstract

PURPOSE:To obtain a shielding material which is capable of easily shielding a noise source in such a manner as to prevent the leakage of noise, generated from an electronic equipment, out of the equipment. CONSTITUTION:A shielding material 14 is chiefly composed of a base material 15, such as a bole, with a mixture of a high permeability material 17 which results in a magnetic shielding material 19 or with a mixture of a conductive material 18 which results in an electromagnetic shielding material 20. This material appears a paste, and can be easily formed in any arbitrary size only by fingers.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a clay-like shielding material which is made of a plastic semi-solid material mixed with a high magnetic permeability material or a conductive material and is used for magnetic and electromagnetic field shielding.

0002

BACKGROUND OF THE INVENTION With the spread and expansion of use of electronic equipment, electromagnetic wave interference has also increased, and countermeasures against interference have become necessary. For this reason, methods such as shielding are used to prevent electromagnetic waves from being radiated to the outside. A specific example is described below. There is a method of enclosing electronic components on a printed circuit board on which electronic equipment is mounted with a metal shielding case for electromagnetic shielding. FIG. 5 is a cross-sectional view of a case in which the device is shielded with a conventionally commonly used metal shield case. In the figure, an IC 2 is mounted on a printed circuit board 1, and a shield case 3 is mounted to surround the IC 2. In addition, we will explain how to shield using copper foil tape. Figure 6 shows, for example, TDK's catalog IEP-066-F (058
910) A perspective view showing a conventional shielding tape shown in UN, which is made of copper foil in the form of a tape. Figure 7 is Figure 6
FIG. A conductive adhesive 5 is applied to the copper foil tape 4 for easy attachment. When in use, as shown in FIG. 8, the copper foil tape 4 is pasted over the IC 2 so as to surround it. What has been described above is a method for shielding electronic components on the printed circuit board 1. Next, a method will be described in which the cable 6 is wound around a ring with high magnetic permeability to blunt the rise of the signal and narrow the radiation noise band. FIG. 9 shows, for example, Tokin's catalog Cat. No
．． The perspective view of the conventional countermeasure method shown in CD-108 is shown. A cable 6 is wound around a ferrite core ring 7 and connected to a printed circuit board 1.

Next, the operation will be explained. As shown in FIG. 5, when it is found that the noise 8 is emitted from the IC 2 on the printed circuit board 1, it is necessary to shield the IC 2 as a countermeasure. As a means for this purpose, a shield case 3 is formed to an arbitrary size so as to cover the IC 2, and is fixed to both sides of the printed circuit board 1 with solder or the like so that there is no gap. Then, noise 8 is shield case 3
I can't go outside anymore. Furthermore, even when the IC 2 is covered with the copper foil tape 4 as shown in FIG. 8, the operation will be explained in the same manner as in FIG. 5, so a description thereof will be omitted here. FIG. 9 shows a method of attenuating noise emitted from the cable 6 by using a ferrite core ring 7 with high magnetic permeability.

0004

[Problems to be Solved by the Invention] In the conventional system, when the noise generation source is a printed circuit board, it is necessary to cover it with a shield case 3 or copper foil tape 4, and when the noise generation source is a cable 6, the ferrite core ring is It was necessary to prepare several types of each type, install, test, and remove each to select the optimal one, which took time and effort.

[0005] This invention was made to solve the above-mentioned problems, and the shield is made of a clay-like material as the main component, so that it can be easily molded by pressure, and it can also be easily attached and removed. The purpose is to obtain wood.

[0006]

[Means for Solving the Problems] The clay-like shielding material according to the present invention is composed of a semi-solid material having plasticity as its main component, and can be easily molded with fingers and easily adapted to the shape of electronic components. This is how it was done.

[0007]

[Operation] The clay-like shielding material of the present invention can be easily molded into any size and shape with fingers according to the size and shape of the area to be treated, and can be easily attached and removed.

[0008]

【Example】

Example 1. FIG. 1 is a sectional view showing an embodiment of the present invention, in which 1 is a printed circuit board and 2 is an IC. In the figure, components such as an IC 2 are mounted on a printed circuit board 1, and both sides of the printed circuit board 1 are covered with a shielding material 14.

The shielding material 14 is the basic base material 1
5 and an additive material 16.

The base material 15 includes a semi-solid oil clay having plasticity, a polymer compound, silicone raw rubber (dimethylpolysiloxane raw rubber, methylphenylpolysiloxane raw rubber, methylvinylpolysiloxane raw rubber, cyano-alkylmethylpolysiloxane raw rubber, fluorocarbon raw rubber). Alkyl
Examples include methyl polysiloxane raw rubber, self-adhesive silicone rubber, fluorinated alkyl silicone rubber, cyanoalkyl silicone rubber), and air-vulcanized one-component silicone rubber.

The additive material 16 can be broadly classified into a high magnetic permeability material 17 and a conductive material 18.

[0012] When a high magnetic permeability material 17 is added to the base material 15, a magnetic shielding material 19 that shields magnetism is produced. Further, when the conductive material 18 is added to the base material 15, an electromagnetic wave shielding material 20 that shields electromagnetic waves can be obtained.

The high magnetic permeability material 17 includes powders such as ferrite, amorphous, and permalloy, and one or more types can be selected.

The conductive material 18 can be selected from one or more of pure copper and copper alloys, aluminum alloys, iron-based alloys including pure iron and stainless steel, powders such as carbon, and fibers.

Magnetic shielding material 1 configured as described above
9 and how to make the electromagnetic shielding material 20 will be described below. Prepare equal amounts of base material 15 such as oil clay and additive material 16 such as high magnetic permeability material 17 or conductive material 18, and mix the high magnetic permeability material 17 or conductive material 18 into the base material 15 little by little. Knead until evenly mixed. The mixing ratio of base material 15 and additive material 16 is 1:
It is 1.

If noise 8 is emitted from the IC 2, for example, as shown in FIG. 2, the IC 2 is surrounded by an electromagnetic shielding material 20 covering both sides of the printed circuit board 1. By doing so, the electric field component noise 8 is prevented from coming out from the electromagnetic shielding material 20 as shown in FIG.

Example 2. In FIG. 3, printed circuit board 1
If noise 8 is emitted from the cable 6 connected above, for example, a loop is formed in the cable 6 and the loop is covered with a magnetic shielding material 19. As a result, noise emitted from the cable 6 is prevented from exiting from the magnetic shielding material 19. The purpose of creating a cable loop is to increase the contact area with the shielding material and enhance the shielding effect.

Example 3. When both low frequency magnetic field component noise 8 and high frequency electric field component noise 8 are output from IC2,
As shown in FIG. 4, the IC 2 is surrounded by a magnetic shielding material 19 on both sides of the printed circuit board 1, and an electromagnetic shielding material 20 is further layered. By doing so, the noise of both the magnetic field component and the electric field component can be shielded.

Example 4. Although the magnetic shielding material 19 and the electromagnetic shielding material 20 have been configured and explained separately, one of the high magnetic permeability material 17 and the conductive material 18 is added to the base material 15.
Similar effects can be obtained by selecting one type or two or more types and mixing them.

Example 5. Although the sources of noise are limited to electronic components such as the IC 2, excluding the cable 6, countermeasures may be required even for the pattern of the printed circuit board 1, and in such cases, an appropriate amount of magnetic shielding material 19 or electromagnetic shielding may be required. Cover the area to be treated with the material 20 or a combination of both.

[0021]

As described above, according to the present invention, the shielding material 14 is made of a plastic, semi-solid, so-called clay-like material. Since it can be used for various purposes, etc., and can be easily removed, the shielding effect can be easily confirmed, which has the effect of shortening the development period and development cost of electronic devices.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a perspective view showing Embodiment 1 of the present invention.

FIG. 3 is a sectional view showing a second embodiment of the invention.

FIG. 4 is a sectional view showing a third embodiment of the present invention.

FIG. 5 is a sectional view showing a conventional shield case.

FIG. 6 is a perspective view showing the entire conventional copper foil tape.

FIG. 7 is a sectional view showing a conventional copper foil tape.

FIG. 8 is a perspective view of shielding with a conventional copper foil tape.

FIG. 9 is a perspective view showing an example of how a conventional ferrite core ring is used.

[Explanation of symbols]

1 Printed circuit board 2 IC 6 Cable 8 Noise 9 Current 14 Shield material 19 Magnetic shielding material 20 Electromagnetic shielding material

Claims (2)

[Claims] Claim 1: Powder of a high magnetic permeability material is added to any of the semi-solid base materials having plasticity, such as oil clay, polymer compounds, raw silicone rubber, and air-vulcanized one-component silicone rubber. A clay-like shielding material characterized by containing. [Claim 2] Powder or fiber of a conductive material is added to any material such as a semi-solid base material having plasticity, such as oil clay, a polymer compound, raw silicone rubber, or an air-vulcanized one-component silicone rubber. A clay-like shield material characterized by containing.