JPH0238472Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electromagnetic shielding plate for electronic equipment, and proposes an electromagnetic shielding plate that is particularly lightweight and can be installed closely to electrical components.

[Prior art and problems to be solved by the present invention]

Weight reduction is an important issue in electronic equipment. Electromagnetic shielding plates also have this problem, and foil-shaped plates are commercially available for this purpose, but they have the disadvantage of having limitations in terms of use. In other words, the foil needs to be attached or fixed to some kind of support. Therefore, copper plates are generally used as electromagnetic shielding plates, but they are heavy and expensive. On the other hand, since electromagnetic shielding plates are conductive, they must not come into contact with other electrical components, so they must be used with an appropriate distance, or an insulating material must be placed between them. I needed to use it.

The object of the present invention is to provide an electromagnetic shielding plate that is lightweight, has a wide range of uses, and can be installed closely to electrical components.

〔structure〕

FIG. 1 is a cross-sectional structural diagram of the electromagnetic shielding plate of the present invention, in which a copper plating layer 12 with a thickness of 3 to 20 μm is formed on one surface of an aluminum substrate 11 of 0.1 mm or more, preferably 0.0.4 mm or more, and the upper layer is A nickel plating layer with a thickness of 2 to 6 μm is formed on the aluminum substrate 11, and an electrical insulating layer 10 is formed on the unplated side of the aluminum substrate 11.
It is made by coating. Materials for this insulating layer include plastics such as polyethylene, polypropylene, fluorine resin, and polyester, rubber,
Appropriate materials such as varnish, epoxy resin, paper, etc. may be used, and the coating may be applied in any appropriate form such as painting, electrodeposition, film adhesion, etc.

Further, the thickness may be determined depending on the required insulation strength.

The thickness of the nickel plating layer 13, the copper plating layer 12, and the substrate 11 are determined by the frequency of the electromagnetic waves to be shielded,
It should be selected based on strength. In other words, this electromagnetic shielding plate shields the source of high-frequency electromagnetic waves from the nickel plating layer 1.
Most of the electromagnetic waves incident on the surface side are reflected, but due to the skin effect, the electromagnetic waves penetrate to a depth of δ=√2.

However, ω: frequency σ: electrical conductivity μ: magnetic permeability Therefore, the electromagnetic wave attenuation characteristics of this electromagnetic shielding plate are determined by the metal used and its thickness. If the temperature of the electromagnetic shielding plate is a problem, the thickness of each plate should be selected taking into consideration the temperature rise.

The electromagnetic shielding plate according to the present invention is also made more useful by supporting one edge of the electromagnetic shielding plate so that it has enough rigidity to be self-supporting. FIG. 2 shows an embodiment for such use.

Reference numeral 21 is a printed circuit board with copper wiring printed on its front and back surfaces, and an integrated circuit 22,
Various circuit components such as a transistor 23 and a resistor 24 are mounted, and the electromagnetic shielding plates 20, 20, 20 of the present invention are arranged so that their mounting positions are divided into four sections.
has been established.

This shielding plate 20 has a rectangular shape having approximately the same width as the printed circuit board 21 and a sufficiently high height compared to the mounted components, and has a plurality of claws 20a, 2 at appropriate positions on the lower edge.
0a, which is inserted into a hole drilled in the printed circuit board 21 and soldered to the conductor portion on the front or back surface of the printed circuit board 21. This soldering is performed on the nickel plating layer 13 side.

Although the nickel plating layer 13 is not necessarily required, if the nickel plating layer 13 is provided, soldering can be easily performed. Furthermore, if the copper plating layer 12 is exposed during long-term storage, it will oxidize, but if the nickel plating layer 13 is provided, it will not be oxidized and a beautiful surface condition can be maintained.

Furthermore, when the nickel plating layer 13 is provided and three types of metals, aluminum, copper, and nickel, are used, there are three peak frequencies of attenuation, and therefore it is possible to provide an effective shield for electromagnetic waves in a wide range of frequencies. can. Furthermore, since the amount of attenuation can be changed depending on the thickness of the plating layer, the degree of freedom in design is correspondingly high.

〔effect〕

The invented product as described above has the following effects.

First, compared to those made of copper plates, they are lighter because they are mainly made of aluminum. Also, although it is heavier than a foil-like material, there are fewer restrictions on its use.
That is, this is because it has independence as shown in FIG.

Since it has such independence, it has the advantage that it can be easily mounted on a printed circuit board or the like.

Next, since the electrical insulating layer is laminated, it is possible to use the electrical component in a state where it is in contact with the surface on which the electrical insulating layer is formed. Therefore, for example, when the proposed product is attached to the inner surface of the casing of an electronic device, the structure can be such that the internal electrical components and the proposed product are in contact with each other, so that the packaging density within the casing can be significantly increased. The present invention has excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional structural view showing an embodiment of the present invention, and FIG. 2 is a perspective view showing an example of a state of use. 10... Electric insulating layer, 11... Substrate, 12...
Copper plating layer, 13...nickel plating layer.

Claims (1)

[Scope of utility model registration request] An electromagnetic shielding board characterized by having a copper plating layer formed on one side of an aluminum substrate and an electrically insulating layer laminated on the other side.