JPH01163059A - Metal foil clad laminated sheet - Google Patents

Abstract

PURPOSE:To obtain an inexpensive shield material excellent in shield effect and easy to manufacture and process, by arranging a metal foil wherein both surfaces are roughened as the inner layer of a laminated sheet. CONSTITUTION:A metal foil 1 wherein both surfaces are roughened is used as an inner layer and base materials 2, 3 are arranged to both surfaces thereof to be integrally laminated to the metal foil 1. As the material of the metal foil to be used, copper, aluminum, nickel or the like are used from the aspect of strength, manufacturing cost and the electromagnetic wave shield effect of the laminated sheet and the thickness thereof is set to about 12-85mum. The roughening of both surfaces is performed by physical or chemical treatment. As the base material used in the integral lamination of the metal foil, glass cloth impregnated with an epoxy resin, a polyester resin, a phenol resin or the like is used and the thickness thereof is set to about 50-800mum in a printed circuit board and a plurality of said cloths are appropriately combined and laminated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a metal foil-clad laminate. More specifically, the present invention relates to a metal foil-clad laminate that is inexpensive and has a high shielding effect, useful as a laminate for shielding electromagnetic waves and high frequencies.

(Background Art) In recent years, as electric/electronic equipment, electronic computers, etc. have become more sophisticated and accurate, countermeasures against electromagnetic waves for these equipment or components have become an extremely important issue. This is because even a small amount of electromagnetic waves can cause these devices to malfunction or become unstable.

As a countermeasure against electromagnetic waves, attempts have been made to shield electronic devices and components from electromagnetic waves.
Efforts have also been made to achieve electromagnetic shielding effects in the frames of electrical and electronic equipment. For example, as an example of such an electromagnetic shielding plate, a double-sided plate or a three-layer plate is known in which glass epoxy substrates in which a glass base material is impregnated with an epoxy resin are laminated.

However, in the case of these conventional glass epoxy double-sided plates, the shielding effect is small, and in the case of the glass epoxy three-layer plate, although the shielding effect is good, the manufacturing cost is high, making it impractical.

In addition, in order to achieve a shielding effect, it has been considered to use a metal plate, but due to issues such as weight reduction, manufacturing cost reduction, and usage restrictions, it is not possible to put it into practical use. Therefore, it is strongly desired to create a shielding material that has excellent electromagnetic shielding effects, is easy to manufacture and process, and is inexpensive as a shielding material for electrical and electronic equipment and parts, such as disk drives and high-frequency PWBs. was.

(Objective of the Invention) The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a shielding material that improves the drawbacks of conventional products, has excellent shielding effects, is easy to manufacture and process, and is inexpensive. It is an object.

More specifically, it is an object of the present invention to provide a metal foil-clad laminate as a new shielding material to replace conventional glass epoxy double-sided plates and glass epoxy three-layer plates.

(Disclosure of the Invention) In order to achieve the above object, the metal foil-clad laminate of the present invention is characterized in that a double-sided roughened metal foil is provided in the inner layer and is laminated integrally with the base material.

This invention is characterized in that a metal foil roughened on both sides is provided as the inner layer of the laminate, but the metal foil used in this case may be any type of metal or alloy. Copper, aluminum, nickel, etc. can be suitably used in terms of zero strength, workability, manufacturing cost, electromagnetic shielding effect of the laminate, etc.

Its thickness can preferably be about 12 μm to 85 μm.

This metal foil is made with roughened surfaces on both sides,
Surface roughening can be easily performed by physical or chemical treatment. The metal foil can also be continuously treated by corona discharge treatment, plasma bombardment, or the like. Chemical treatment also includes treatment with etching agents.

Glass cloth, glass cloth,
Glass nonwoven fabric, glass mat, resin-impregnated glass obtained by impregnating these glass cloths with epoxy resin, polyester resin, phenol resin, etc. can be used. For example, in the #I board, the thickness is 5
The thickness may be approximately 0 to 800 μm, and a plurality of layers may be appropriately combined and laminated.

The attached drawings show examples of metal foil-clad laminates of the present invention.

For example, the cross-sectional view in Figure 1 shows a metal foil (
1) is used as an inner layer, and base materials (2) and (3) are arranged on both sides of the inner layer to form an integral layer. In this example, since the metal foil (1) which is roughened on both sides is used as the inner layer, it has an excellent electromagnetic wave shielding effect and can be used as a shielding material for disk drives and high frequency PWBs. The adhesion between the metal foil (1) and the base materials (2) and (3) becomes extremely good due to the surface roughening of the metal foil.

FIGS. 2 and 3 show another example of the invention. In the case of the laminate shown in Figure 2, double-sided roughened metal foil (
1) is used as an inner layer, base materials (2) and (3) are arranged on this, and a metal foil (4) is further arranged on the base material (2) side to form an integrated lamination.

Further, in the case of the example shown in FIG. 3, metal foils (4) and (5) are arranged on the outermost surfaces of both sides of the base materials (2) and (3), and are laminated and integrated.

In either case of FIG. 2 or FIG. 3, the base materials (2) and (3) can be used in an appropriate combination in the required number as in FIG. The metal foil (4) and/or (5) may be similar to the metal foil (1) with roughening on both sides, or may be made of an unroughened metal or alloy such as copper, aluminum, nickel, stainless steel, etc. It may also be a metal foil.

In the case of the examples in FIGS. 2 and 3, metal foils (4) (5
) can also be processed to form a circuit.

For example, the metal foil-clad laminate for electromagnetic shielding of the present invention, which can be exemplified as above, can be manufactured by a conventional multi-stage pressing method or a continuous method. Examples of this are shown in FIGS. 4 and 5.

Figure 4 shows the pressing method, for example, double-sided 1
1F heated metal foil (1), base material (2) (3) laminated in the required number in advance, or its prepreg, and metal foil (4) (5), if necessary, via adhesive,
They are laminated and integrated by heating and pressure molding using a press mold (6). Temperature around 140~220℃, 30~85kg/
It is possible to perform heating and pressure molding under a pressure of about CD or more.

The metal foil (1) roughened on both sides is in close contact with the base materials (2) and (3), and a laminate with excellent electromagnetic shielding effect can be obtained.

It can also be manufactured by a continuous method as shown in FIG.

Metal foil (1) with roughening on both sides sent out from roll (7)
Base materials (2) and (3) or their prepregs are coated on both sides of the
Metal foils (4) and (5) fed out from rolls (9) and (10) are placed on these elongated laminates (8), and heated and pressed rolls (11) and (12 ) can be laminated and integrated by heating and pressurizing. Also in this case, an adhesive can be used if necessary.

Next, embodiments of the present invention will be shown, and the structure and effects of the present invention will be explained in more detail. Of course, the invention is not limited to the following examples.

(Example 1) Both sides of a 100 μm copper foil were roughened by abrasion treatment,
Using this as an inner layer, a laminate having the structure shown in FIG. 1 was produced by a pressing method. Epoxy glass cloth was used as the base material, and the thickness of the laminate was 0.8-.

Two antennas were placed on both sides of this laminate at a distance, and the shielding effect of the laminate was evaluated.

The distance between the antennas is 30cm, and the frequency is 30M.
Hz.

The standard value of electromagnetic waves when no laminate is placed is 78 dBμV
However, when the laminate was placed in the middle of the antenna, it was -20.0 dBμV. Shield effect is 98
．． 0 dB, which is extremely excellent as is clear from comparison with the following comparative example.

(Comparative Example) The shielding effect was evaluated in the same manner as in Example 1 using a 0.8 am thick double-sided epoxy glass plate without using metal foil for the inner layer. The reference electromagnetic wave had a voltage of 78 dBμV, but when this epoxy glass double-sided plate was provided at the middle position of the antenna, the voltage was 71.0 dBμV. The shield effect is
It was only 7.0 dB.

(Examples 2 to 8) Regarding the laminate of Example 1, the frequency was set to 50 to 1000 M.
The shielding effect was evaluated by changing the frequency to Hz.

As shown in the table below, 60d at any frequency.
A shielding effect of B or higher was observed.

(Effects of the Invention) As explained in detail above, the present invention provides a metal foil-clad laminate with extremely excellent shielding effect.

This laminate not only has a much better electromagnetic shielding effect than conventional double-sided glass epoxy, but it can also be manufactured efficiently using metal foils such as copper and aluminum, and is also cost-effective. Advantageous compared to 3-layer epoxy board.

Furthermore, since the metal foil has roughened surfaces on both sides, it not only has a shielding effect but also has excellent adhesion to the base material.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, and FIG. 3 are sectional views each illustrating the structure of the laminate of the present invention. FIGS. 4 and 5 are cross-sectional views each illustrating a method for manufacturing a laminate according to the present invention. 1... Double-sided roughened metal foil, 2.3... Base material, 4.5
... Metal foil, 6... Press mold, 7... Roll,
8... Laminate, 9.10... Roll, 11.1
2...Heating pressure roll. Agent Patent Attorney Toshi Nishizawa Otsutsu 1
Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] (1) A metal foil-clad laminate characterized in that a double-sided roughened metal foil is provided as an inner layer and is laminated integrally with a base material.