JP2001284880A - Electromagnetic wave shield - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic wave shield which has a superior air tightness or elasticity, softness and formability, is wide in application and development mainly as an EMC material and greatly improved about the material stability in weather resistance, etc., such as continuously holding a high electromagnetic shielding ability even in a high temperature and high bumid environment, etc., and has a more effectively strengthened bonding, etc., to elastomer material boards, thus obtaining higher reliability. SOLUTION: The shield is made by forming an electromagnetic shield film 1 on the surface of an elastomer material board 2. The film is made of an Ag alloy containing Pd 0.1-3.0 wt.% and at least one element 0.1-3.0 wt.% among Cu, Au, Ti, Cr, Ta and Mo, added to a main component Ag. One or more shield films 1 may be formed on the surface of the board 2 according to the use of the shield superior in flexibility, this making stable in temperature and chemically. Thus, the application to various uses can be examined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable information terminal device such as a notebook personal computer or a portable telephone, a display device such as an electronic device, a liquid crystal display (LCD) or a plasma display in a transparent opening. Shields electromagnetic waves, infrared rays, and near infrared rays emitted from a display screen such as a panel (PDP). For example, the present invention relates to an electromagnetic wave shield used to prevent radio wave harm caused by an external electromagnetic wave entering an electronic device or the like, and particularly, is attached to the inside of the above-described various electromagnetic wave shields or has an outer shape. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic wave shield excellent in flexibility and flexibility that can be bent and attached along.

[0002]

2. Description of the Related Art In the information society in recent years, as seen in the development of mobile communications such as satellite broadcasting systems and portable information terminal devices, the electromagnetic wave environment has become increasingly diversified and complicated. The evils along with the benefits they bring are becoming apparent. For example, when an external electromagnetic wave from the outside (outside) enters an electronic device or the like and does not lead to noise adverse effects,
In addition, there is a concern that electromagnetic waves leaking from portable information terminal devices such as notebook personal computers and mobile phones adversely affect the human body and adversely affect social life. EMC (Electro Magnetic Comp)
Ability, that is, electromagnetic compatibility (sometimes referred to as electromagnetic compatibility) is an element that can solve various engineering problems caused by electromagnetic waves.

Heretofore, metals have mostly occupied EMC materials for shielding external electromagnetic waves and leakage electromagnetic waves from personal computers and the like (hereinafter the former). Attempts to obtain conductivity by blending metal powder or carbon black with an elastomer material have also been made (hereinafter the latter).

[0004]

However, the former E
In MC materials, products and elements that require EMC technology in recent years have diversified rapidly, and it has become impossible to respond to various functions that are not required only by metal. For example,
Bending followability to complex shapes and filling of unsteady space,
Various problems have occurred, such as the difficulty in applying the method to the problem of weight reduction and corrosion resistance to rust and the like. On the other hand, the latter, which is filled with metal powder, has many disadvantages such as a change with time mainly due to metal oxidation and a loss of mechanical properties such as elasticity and strength of the elastomer itself. It is hard to say. Although elastomers filled with carbon black have been diversified into conductive rollers, rubber contacts, and the like, they are hardly used as EMC materials because of the limited conductivity obtained. As described above, since the conventional electromagnetic wave shield has problems in bending followability to complicated shapes, corrosion resistance, and weather resistance and abrasion resistance, etc., it is completely adopted as an EMC material ( Application) is impossible.

[0005] The present invention has been made in view of such a conventional situation, and a purpose thereof is to provide an electromagnetic wave shielding film made of an Ag alloy material on a surface of a substrate made of an elastomer material. It is an electromagnetic wave shield with excellent properties,
Flexibility, shape flexibility (bendability to complicated shapes)
With a wide range of applications mainly as an EMC countermeasure material,
Further, the material stability such as weather resistance, which is that high electromagnetic wave shielding ability is continuously maintained even in an environment such as high temperature and high humidity, is remarkably improved, and the bonding property with the elastomer material substrate ( Adhesion) is more effectively strengthened,
An object of the present invention is to provide an electromagnetic wave shield capable of obtaining higher reliability.

[0006]

[Means for achieving the object] To achieve the object,
In the present invention, the electromagnetic wave shielding effect is high and chemically stable,
In addition, an electromagnetic wave shielding film made of an Ag alloy material containing Ag as a main component, Pd, and at least one or more of Cu, Au, Ti, Cr, Ta, and Mo that can be easily manufactured. Is formed on the surface of a conductive elastomer material substrate. here,
The thickness of the electromagnetic wave shielding film is preferably, for example, about 10 to 500 nm in consideration of, for example, bending followability to a complicated shape. Further, the electromagnetic wave shielding film, a single film according to the use of the electromagnetic wave shield,
Alternatively, by forming a multilayer film of two or more films on the surface of the substrate, it is stable in temperature and chemical stability, and can be applied to various uses. Further, the electromagnetic wave shielding film,
Pd is added within the range of 0.1 to 3.0 wt%, and C is further added.
It is formed from an Ag alloy material to which at least one or more of u, Au, Ti, Cr, Ta, and Mo is added in a range of 0.1 to 3.0 wt%. Examples of the elastomer material include natural rubber, chloroprene rubber, and EPDM (rubber-like terpolymer of ethylene / propylene and diene).

In the present invention, the Ag alloy material is a vapor deposition material or a sputtering target material, and the electromagnetic wave shielding film is formed on the surface of the substrate by a film forming process such as a vapor deposition method or a sputtering method.

[0008] In the present invention, on the above-mentioned electromagnetic wave shielding film,
A protective film made of a material having excellent corrosion resistance and weather resistance, or a protective film made of a material having excellent wear resistance is formed.

Further, in the present invention, an adhesion promoting base film for promoting adhesion between the substrate and the electromagnetic wave shielding film is formed between the substrate and the electromagnetic wave shielding film. In addition, as a material of the adhesion promoting base film, ITO (In oxide and Sn oxide) is used.
Composite oxide), IrO ₂ , ZnO ₂ , SiO ₂ , Ti
At least one selected from O ₂ , Ta ₂ O ₅ , and ZrO ₂ ;
Alternatively, a metal oxide material composed of two or more kinds containing these as main components is preferable. Or Si, Ta, Ti, M
It is preferable to use at least one selected from o, Cr, and Al, or a material composed of two or more of these as main components.

[0010]

Embodiments of the present invention will be described. FIG. 1 is a cross-sectional view showing an embodiment of the electromagnetic wave shield of the present invention, in which an electromagnetic wave shield film 1 made of an Ag alloy material described later is adhered to a surface of a substrate 2 made of at least a conductive elastomer material. It is formed by lamination with the ground film 3 interposed.

[0011] In the present invention, the self-diffusion energy for the heat held by Ag itself is relaxed to suppress the phenomenon of clouding due to surface diffusion which is likely to occur when heated to at least about 100 ° C. is important. That is, Ag is known to be the material having the best electromagnetic wave shielding ability. However, for example, a problem that self-diffusion energy for heat is active is likely to occur. For this reason, when heat of about 100 ° C. is applied even temporarily, a diffusion phenomenon occurs on the surface, and the Ag itself loses its gloss and becomes cloudy. In other words, the characteristics of Ag itself, which is superior in electromagnetic wave shielding performance, are reduced.

Therefore, Ag has a very good thermal conductivity and has a characteristic of easily absorbing and saturating heat in atomic units. Therefore, Ag is required to reduce thermal conductivity and to suppress active movement between atoms. An experiment was carried out by adding Pd, which is an atom forming a solid solution with respect to Ag, in a composition range of 0.1 to 4.0% by weight. First, each of sputtering of Ag and Pd is mounted on a sputtering apparatus, and the discharge amounts of Ag and Pd are controlled with a specific RF power to obtain Ar and Pd.
The (argon) gas is arbitrarily set between 0.1 and 3.0 Pa, and the two materials are sputtered simultaneously. In other words, the amount of addition of several types of Pd is changed by simultaneous sputtering, and Ag is added.
An alloy material film was formed. At this time, the test specimen
Using a quartz substrate of 100 mm × 100 mm × 1.1 t, the substrate temperature during the sputtering process is normal temperature (around 25 ° C.), and only Ar gas is used as a sputtering gas.
The film was formed with a film thickness of 20 nm in a high vacuum atmosphere of a ultimate vacuum degree of 3 × 10E-6 Pa. The reason for forming a film in a high vacuum atmosphere is to suppress the impurity gas and the like from being dependent on the grain boundaries of the alloy film and to confirm the original physical properties of the material by forming a dense film. That's why.

An Ag alloy material thin film containing Ag formed as a main component and Pd added with several kinds of material compositions thereon is placed on a hot plate in the air and left for about 2 hours to reduce the white turbidity. A heating test was conducted to observe the presence / absence and the temperature at which clouding started. At this time, the heating method of the hot plate is a resistance heating method, and the heating temperature is 2
The heating rate was set to 50 ° C. and the heating rate was set to 20 ° C./min. Table 1 shows the test results.

[0014]

[Table 1]

In general, it is well known that the addition of Pd improves the lack of weather resistance in a high-temperature and high-humidity (humid) environment possessed by Ag. No significant difference as shown in Table 1 can be confirmed with respect to the surface diffusion resistance of No. 1, and a remarkable superiority can be confirmed as compared with Ag with respect to the reduction of clouding due to the addition of Pd. Did not. Further, since it was confirmed that the electromagnetic wave shielding ability was reduced by about 2 to 3% after heating as compared to before heating, the effect of preventing surface diffusion due to the addition of Pd could not be confirmed.

Embodiment 1 In the present invention, first, Ag, which is a main component, is added in an amount of 0.1 to 0.1%.
3.0 wt% Pd is added, and Cu, Au, Ti, C
At least one element of r, Ta, and Mo was added to form an Ag alloy material thin film composed of at least three elements, and suppression of surface diffusion due to heat was studied. At this time, the addition amount of at least one element among Cu, Au, Ti, Cr, Ta, and Mo is 0.1 to
3.0 wt%. As a method of forming a thin film, one selected from a sputtering target material of Ag and Pd, and further, any one of Cu, Au, Ti, Cr, Ta, and Mo is mounted on an RF magnetron sputtering apparatus. By simultaneously sputtering three metal elements, a thin film made of a three-element Ag alloy material was formed. At this time, the test substrate was 100 mm x 100 mm x 1.
Using a 1 t quartz substrate, the substrate temperature during the sputtering process is normal temperature (around 25 ° C.), and the sputtering gas is A
Using only r (argon) gas, the film was formed in a high vacuum atmosphere having a degree of ultimate vacuum of 3 × 10E-6 Pa with a film thickness of 20 nm, which is the same as that of the above-described Ag-Pd two-element alloy.

The test sample in this method contains A as the main component.
g, Pd is added in an amount of 0.1 to 3.0 wt%, and Cu,
A three-element Ag alloy material thin film obtained by adding 0.1 to 3.0 wt% of any one of Au, Ti, Cr, Ta and Mo is directly formed on the surface of a quartz substrate with a thickness of 20 nm. In the same manner as described above, a heating test was performed in which the sample was placed on a hot plate maintained at a heating temperature of 250 ° C. and left for 2 hours, and the presence or absence of cloudiness and the temperature at which clouding was started were observed. The test results are shown in Tables 2 and 3.

[0018]

[Table 2]

[0019]

[Table 3]

Then, Pd is added to Ag or Ag by 0.1 to 0.1%.
In the case of the two-element Ag-Pd alloy material added with 4.0 wt%, as is apparent from Table 1 above, the surface of the film becomes clouded and the electromagnetic wave shielding ability is reduced to a considerable extent. Ag is used as a main component and Pd is set to 0.1 to 3.0.
wt%, and Cu, Au, Ti,
Any one of Cr, Ta, and Mo is used in 0.1 to 3.
As can be seen from Tables 2 and 3, in the three-element Ag alloy material to which 0 wt% was added, no clouding phenomenon or reduction in electromagnetic wave shielding ability was observed in all the material composition ranges.

Then, the quartz substrate on which the Ag alloy material films formed in various material composition ranges subjected to the heating test at 250 ° C. are further left on a hot plate heated to 400 ° C. for 2 hours. In any case, no clouding or reduction in electromagnetic wave shielding ability was observed in any of the material composition ranges.

In addition, Cu, Au, T
Any one of i, Cr, Ta, and Mo is 0.1 to
As described above, a test sample in which a two-element Ag alloy material thin film to which 3.0 wt% was added was directly formed on a quartz substrate with a thickness of 15 nm by a sputtering method at the same time was heated at both 250 ° C. and 400 ° C. When a heating test was performed to observe changes over time, it was confirmed that all the films became cloudy and the electromagnetic wave shielding ability was reduced.

As described above, the content of Ag as the main component is 0.1 to
3.0 wt% of Pd is added, and 0.1 to 3.0 wt% of Cu, Au, Ti, Cr, T
By using a three-element Ag alloy material obtained by adding any one of a and Mo, a significant improvement in heat resistance is recognized, and furthermore, the electromagnetic wave shielding effect of Ag itself is reduced. It has been found that the high shielding ability can be maintained without deteriorating.

Example 2 In the present invention, when a heating test was performed on the electromagnetic wave shielding film 1 made of an Ag alloy material having various material composition ranges having a high heat resistance, a slight peeling was observed at the end of the thin film. Was observed, and it was confirmed that the adhesion was at least weak to a substrate made of a specific material. Therefore, the adhesion between the substrate and the electromagnetic wave shielding film 1 made of a three-element Ag alloy material of each material composition range was determined. investigated.

Therefore, in the present invention, in order to confirm the adhesion of the electromagnetic wave shielding film 1 made of the three-element Ag alloy material in each of the above-described material composition ranges, at least a conductive elastomer material, in particular, various materials described below. Substrate 2 consisting of
After forming a thin film having a thickness of 15 nm directly on the surface of the substrate by a three-element simultaneous sputtering method as in the past, a test for confirming adhesion by a peel test method was attempted. Then
Since it was confirmed that the adhesiveness was not necessarily high for any substrate 2 made of various materials, the electromagnetic wave shielding film 1 made of a three-element Ag alloy material consisting of various material compositions and a substrate 2 made of various materials was used. In the meantime, the adhesion was further studied by forming a specific adhesion promoting base film 3 which promotes the adhesion between them as an intermediate base.

As an elastomer material for forming the substrate 2,
Natural rubber, chloroprene rubber, EPDM (rubber-like terpolymer of ethylene / propylene and diene) and the like can be mentioned.

The material of the adhesion promoting base film 3 is materially stable with respect to the substrate 2 made of oxygen or the above-mentioned various materials. Further, the material of the electromagnetic wave shielding film 1 made of an Ag alloy material of at least three elements is used. Considering that adhesion is good, Si, Ta, Ti, Mo, Cr, Al, ITO (composite oxide of In oxide and Sn oxide), IrO ₂ , ZnO ₂ ,
After forming SiO ₂ , TiO ₂ , Ta ₂ O ₅ , ZrO _2, etc. on the surface of the substrate 2 made of various materials by the RF sputtering method, various kinds of the three-element simultaneous sputtering method are performed thereon as in the past. When an electromagnetic wave shielding film 1 made of a three-element Ag alloy material having various material composition ranges was formed and a peel test was performed, natural rubber or chloroprene rubber was obtained by interposing an adhesion-promoting underlayer 3 as an intermediate substrate. Or E
It has been found that the adhesion of the electromagnetic wave shielding film 1 to the substrate 2 made of various materials such as PDM is greatly improved, and the bondability with the substrate 2 made of various materials is further effectively enhanced.

In this case, the substrate 2 made of various materials
As the adhesion promoting base film 3, Si, Ta, Ti, Mo,
Cr, Al, ITO, ZnO_Two, SiO_Two, TiO_Two, T
a_TwoO _Five, ZrO_TwoIs desirable, but a group consisting of various materials
When examining on the surface of the plate 2, ITO, ZnO_Two, Si
O_Two, TiO_Two, Ta_TwoO_Five, ZrO_TwoMetal oxide thin film
Is desirable. The reason is that natural rubber or chlorop
The substrate 2 made of ren rubber or EPDM has a specific purity and material.
In the case of quality, gas generation is very high. In addition, metal
Strong reaction with raw gas. In addition, the contact to make close contact with the Ag alloy material
A reactive floating body film (for example, oxide film etc.) may be formed at the interface.
It is difficult to consider that it is appropriate because of its high efficiency.
You.

Also, the adhesion promoting base film 3 is formed by sputtering.
Is formed on the surface of the substrate 2, when the sputtering method is performed in a vacuum atmosphere, the substrate made of natural rubber, chloroprene rubber, or EPDM is switched during switching from the atmosphere to a vacuum to evacuate the atmosphere in the apparatus. In the case of (1), a gas is generated.
This is because the interface with the substrate tends to be unstable.

An important issue when studying the adhesion-promoting base film 3 is whether or not the film can be easily formed. For example, Si, Ta, Ti, Mo, C
Metal films such as r and Al can be formed by vapor deposition, sputtering, C
Since the film can be formed by any of the VD method and the ion plating method, it can be interlocked with a method of forming at least a three-element Ag alloy material film.
General utility can be considered high.

Also, ITO, ZnO ₂ , SiO ₂ , Ti
Metal oxide thin films such as O ₂ , Ta ₂ O ₅ , and ZrO ₂ can be easily formed by a vapor deposition method, a sputtering method, or an ion plating method. As for the AR (anti-reflection) coat to be formed, the adhesion promoting base film 3 is formed on the surface of the substrate 2 made of various materials, and the electromagnetic wave shielding film 1 made of an Ag alloy material of at least three elements for the purpose of electromagnetic wave shielding. Is formed at a thickness of 0.5 to 1.2 nm, and an AR coat is formed on the top of the monitor to obtain a CRT monitor (C
RT) and a remarkable effect as an effect of shielding against electromagnetic waves, which has been a problem in liquid crystal display devices, could be confirmed.

Example 3 As described above, Ag was used as a material for the electromagnetic wave shielding film 1 in the case of surface diffusion, in air, or when natural rubber, chloroprene rubber, or an EPDM substrate 2 was used.
Since the discoloration effect due to the gas and the like emitted from the substrate 2 is strong, it has been determined that the versatility is not high and has been a problem.

Therefore, in the present invention, 0.1 to 3.0 wt% of Pd is added with Ag as a main component, which has been confirmed to have corrosion resistance and durability against heat resistance and discoloration, and Cu, Au,
0.1 of any one of Ti, Cr, Ta, and Mo
A study was conducted to determine what shielding effect can be obtained with respect to the electromagnetic wave shielding by the three-element Ag alloy material added by about 3.0 wt%.

As a test sample of this method, the three-element Ag alloy described above was applied to the surface of all substrates 2 made of various materials such as natural rubber, chloroprene rubber, or EPDM by a three-element simultaneous sputtering method as before. An electromagnetic wave shielding film 1 made of a material was formed, and the film was measured by a KEC method (a device devised by Kansai Electronics Promotion Center) to confirm the electromagnetic wave shielding ability. Here, a laminated structure in which the electromagnetic wave shielding film 1 made of an Ag alloy material of each material composition range is directly formed on all the substrates 2 made of various materials described above, and an intermediate base such as ITO, ZnO ₂ , A laminated structure in which an adhesion promoting base film 3 made of SiO ₂ or the like is formed on the surface of the substrate 2 and an electromagnetic wave shielding film 1 is formed thereon (see FIG. 1).
The analysis of the electromagnetic wave shielding ability was carried out at the same time. Furthermore, it was also checked whether there was any difference between the Ag alloy material itself and the intermediate underlayer formed, and the Ag alloy material thin film formed on the intermediate underlayer.

Then, for the electromagnetic wave shielding effect, Au,
It can be confirmed that there is a significant difference as compared with the electromagnetic wave shielding film made of a material such as Al, Cu, and Ag. In the case of an Ag alloy material composed of at least three elements, the electromagnetic wave could not be obtained with the material. It was confirmed that it was possible to obtain a high electromagnetic wave shielding ability with respect to the shielding effect. Also, for example, from the low frequency range of 100 MHz, 1
At least about 30 dB over a wide range up to GHz
It was confirmed that the sheet exhibited an electromagnetic wave shielding characteristic of (the intensity of the electromagnetic wave was about 0.1% of the original attenuation).
The visible light transmittance is 70.4% and the solar light transmittance is 5
8.2%. Also, as an intermediate base, I
In the case of an electromagnetic wave shielding body having a laminated structure in which an adhesion promoting base film made of TO, ZnO ₂ , SiO _2, etc. is formed, and an electromagnetic wave shielding film 1 made of at least three elements of an Ag alloy material is formed thereon, a single layer ( No reduction in the shielding performance against the electromagnetic wave shielding effect was observed even when compared with the case of the single-layer (single-layer) electromagnetic wave shielding film, and the high shielding ability was maintained as in the case of the single-layer (single-layer) electromagnetic wave shielding film It was confirmed that it was done.

In this case, preferably, ITO and ZnO are used.
_By providing a conductive oxide such as 2 between the substrate 2 and the electromagnetic wave shielding film 1 as the adhesion promoting base film 3, it was confirmed that the electromagnetic wave shielding effect was higher than at least when SiO ₂ was provided. did it.

In this case, it is desirable that the material of the adhesion promoting base film 3 has a lower resistance. Since the resistance is low and a significant difference can be confirmed by being a non-magnetic conductive film, ITO is more effective at least when ZnO ₂ is used to obtain a higher electromagnetic wave shielding ability than ZnO _2. That was confirmed. The reason for this is that when an Ag alloy material of at least three elements and a specific intermediate base film are provided between the Ag alloy material thin film and the substrate for the purpose of shielding electromagnetic waves, and an electric field is applied to the multilayer film itself, A conduction current flows inside the multilayer film, and this electric energy is converted into heat energy. Further, a heat generation mechanism that converts the heat energy into heat energy is mainly caused by absorption of electromagnetic waves and conduction loss. Because it happens.

The effect of this conduction loss is high depending on the amount of the conduction current flowing with a small resistance, so that the lower the resistance of the electromagnetic wave shielding film, the more significant the difference becomes. But,
For Ag, Al, and Cu, the movement of the atoms of the material itself, that is, the heat generation mechanism that converts electric energy into heat energy by the electromigration phenomenon is attenuated with the passage of time. Provided, the damping action has been reduced, but Pd containing 0.1 to 3.0 wt.
%, And 0.1 to 3.0 wt% of any one of Cu, Au, Ti, Cr, Ta, and Mo is added. It has been found that the damping effect is significantly reduced because the movement is not active.

In addition, here, the conductivity represented by ITO and ZnO is
It is not an electrically conductive oxide but is, for example, an insulating material.
SiO_Two, TiO_Two, Ta_TwoO_Five, ZrO_TwoSuch as dielectric
When an intermediate base is interposed between the Ag alloy material and the substrate
In the case, the effect of the high conduction loss possessed by the Ag alloy material
In addition, electromagnetic wave energy at high frequencies called dielectric loss
The effect of the absorption of the
In order to obtain a high magnetic wave shielding effect,
Conductive as metal oxide film interposed as ground film
There is no need to limit the material. Ag at least as a main component
Then, Pd is added in an amount of 0.1 to 3.0 wt%, and Cu and A are further added.
u, Ti, Cr, Ta, Mo
Ag alloy material of three elements added by 0.1 to 3.0 wt%
In the electromagnetic wave shielding film 1 formed by the material, S
Metal film of i, Ta, Ti, Mo, Cr, Al, etc.
Is ITO, IrO _Two, ZnO_Two, SiO_Two, TiO_Two, Ta
_TwoO_Five, ZrO_TwoEtc. of metal oxide films and metal composite oxides
Ag alloy material film and substrate
If it is interposed as an intermediate base film,
No difference, high electromagnetic wave shielding in any case
The effect was confirmed.

Example 4 Further, as an Ag alloy material which has so far been excellent in corrosion resistance and heat resistance, a two-element Ag-Pd alloy obtained by adding 1 to 3 wt% of Pd to Ag, or a 1 to 1 element in Ag 10w
Ag-Au alloys to which t% Au is added are widely known. However, even if an alloy film formed using any of the Ag-Pd alloy and the Ag-Au alloy is used, high-temperature, high-humidity (high humidity) When the weather resistance test was performed in an environment, black spots were observed.

Therefore, when the black spots were observed with an optical microscope and observed, the black spots reached the solid solution limit of the H2 melting action of Pd, and turned black to cause an excitation reaction to become protrusions. Therefore, it was found that, for example, stability was lacking for long-term reliability in high humidity or localization with high humidity in the rainy season or the like.

It is well known that Ag and Au are solid alloys in which the solid solution is completely dissolved. However, this Ag—Au alloy film is not rich in chlorine and other halogen-based elements. For this reason, air was mixed during the weather resistance test, and it was found that such black spots were obtained by atomic bonding with chlorine and iodine contained in the air.

Also, as shown in Table 1 above, the binary alloy of Ag-Pd does not have high heat resistance, as shown in Table 1 above, because of its high stability against heat rays concentrated from sunlight. Known problems.

Therefore, in the present invention, Pd is contained in a content of 0.1 to 3.0 mainly containing Ag which has been confirmed to have high heat resistance.
wt%, Cu, Au, Ti, Cr, Ta, M
a three-element Ag alloy material obtained by adding 0.1 to 3.0 wt% of any one of the above-described materials to a temperature of 90 ° C. and a humidity of 90 ° C.
An experiment was conducted to find out what results can be obtained with respect to the weather resistance in a high-temperature, high-humidity (humidity) environment in comparison with an Ag-Pd alloy having at least two elements.

In this method, as described above, natural rubber or chloroprene rubber or E
On the surface of all substrates 1 made of various materials such as PDM,
An electromagnetic wave shielding film 1 made of a three-element Ag alloy material of each of the above-described material composition ranges is formed, and it is checked whether there is any change with time in a high-temperature and high-humidity atmosphere at a temperature of 90 ° C. and a humidity of 90%. saw. At this time, all the substrates 2 made of various materials are used.
And Pd containing 0.1 to 3.0 wt% with Ag as a main component.
%, And further, a directly formed three-element Ag alloy material obtained by adding 0.1 to 3.0 wt% of any one of Cu, Au, Ti, Cr, Ta, and Mo. ITO, ZnO ₂ , ZnO ₂ -Al ₂ O ₃ composite oxide, Si
A weather resistance test was conducted simultaneously with those obtained by forming O _{2 and the} like. At the same time, it was also checked whether there was any difference between the case where the Ag alloy material itself and the above-mentioned adhesion promoting base film 3 were formed as an intermediate base film and the Ag alloy material was formed on the base film.

Then, Pd is made 0.1 with Ag as the main component.
To 3.0 wt%, and further, Cu, Au, Ti, C
Any one of r, Ta, and Mo is 0.1 to 3.0.
Even in the case of a single layer (single film) of an electromagnetic wave shielding film formed of a three-element Ag alloy material added by wt%, as shown in FIG. Even when the electromagnetic wave shield is formed using the adhesion-promoting base film 3 made of a material selected from ITO, ZnO ₂ , and SiO _{2 as the} intermediate base, it is compared with a single-layer (single-layer) Ag alloy material film. It was confirmed that the weather resistance was high.

As a result, Pd containing Ag as a main component
Of 0.1 to 3.0 wt%, and further, Cu, Au,
0.1 of any one of Ti, Cr, Ta, and Mo
In the case of a three-element Ag alloy material film with an addition of up to 3.0 wt%, even if an oxide is arbitrarily formed between the Ag alloy material film and the substrate as an upper film, the heat resistance and the weather resistance are not dependent on the underlayer. It has been confirmed that it has high electromagnetic wave shielding ability, and that it is highly useful as an electromagnetic wave shielding body for recent EMC countermeasure materials, such as a wide range of applications.

Further, in the present invention, 0.1 to 3.0 wt% of Pd containing Ag as a main component is added, and Cu, Au, Ti,
In order to confirm the chemical stability of an Ag alloy material film composed of three or more elements in which at least one element of Cr, Ta, and Mo is added in a total of 0.1 to 3.0 wt% in total. Using a test sample in which an electromagnetic wave shielding film 1 having a thickness of 15 nm was formed on the surface of a substrate 2 made of various materials such as natural rubber, chloroprene rubber, or EPDM by a ternary simultaneous sputtering method as before, Temperature 90 ° C,
It was left for 24 hours in a high-temperature, high-humidity (humid) environment at a humidity of 90%, and its appearance and changes over time in electromagnetic wave shielding characteristics were observed. Tables 4 and 5 show the test results.

[0049]

[Table 4]

[0050]

[Table 5]

As is clear from Tables 4 and 5, since no change with time was observed in the material even after standing for 24 hours, it was formed on the surface of a substrate made of various materials such as natural rubber, chloroprene rubber or EPDM. Ag is used as a main component, and Pd is added in an amount of 0.1 to 3.0 wt%.
The electromagnetic wave shielding ability of a three-element Ag alloy material film formed by adding 0.1 to 3.0 wt% of any one of u, Ti, Cr, Ta, and Mo was determined by the KEC method (Kansai Electron Promotion Center devised). Device) and observed.
In a wide range from the low frequency range of 1 MHz to the 1 GHz range,
No decrease in electromagnetic wave shielding ability was confirmed. Like this
The electromagnetic wave shielding film 1 made of a three-element Ag alloy material containing Ag as a main component has high chemical stability and is not limited to all substrates 2 made of various materials such as natural rubber, chloroprene rubber, or EPDM. I understood that.

Separately from this, the electric field intensity attenuation rate (dB) from the low frequency range of 100 MHz to the 1 GHz range by the near-field measurement of the electromagnetic wave shield obtained by the present invention is 20 dB.
Because of the above requirements, the radio wave absorptivity (dB) in the low frequency range of 100 MHz to the 1 GHz range,
The flexibility (cm) was measured. For the measurement of flexibility, the test sample (the electromagnetic wave shield obtained in the present invention) cut into an appropriate size (for example, a strip having a width of 10 mm) was gradually pressed from the end of the test table while pressing the end. The test sample was taken out, and the index was obtained by measuring the length of the test sample on the bench at the time when the hanging portion became just 90 °. Table 6 shows the measurement results. The near field means the electrolysis at a distance of λ / 6 wavelength or less when the wavelength is λ in radio wave engineering. Also, the electric field intensity attenuation rate is
It is an index of the electromagnetic wave shielding ability, and the electromagnetic wave shielding ability of the material is measured by an automatic measuring device that makes the measurement principle the same.

Comparative Example As a comparative example, 100 parts of a vinyl group-containing polydimerylsiloxane having an average degree of polymerization of about 6,000 and containing 0.06% of a merylvinylsiloxane unit, which is a dimethylvinylcytyl group, at both terminals was added to conductive carbon. Furness Black "# 3030B" (manufactured by Mitsubishi Chemical Corporation) 40 as black
Parts and 10 parts of silicon earth were charged into a kneader and kneaded, and then 2,5-dimethyl-2,5-di-t was used as a crosslinking agent.
1.5 parts of butyl peroxyhexane were added to obtain a uniform silicone bomb compound. Then, a test sample was prepared by forming a rubber plate having a thickness of 1 nm and a side of 100 mm on each side by press molding the compound at 170 ° C. for 10 minutes and vulcanizing at 200 ° C. for 4 hours. In addition, as a sample for measuring the electromagnetic wave absorption capacity, a thickness of 7.
A rubber plate having a thickness of 5 nm and a side of 50 mm was prepared by the same method and procedure as described above.

[0054]

[Table 6]

As is apparent from Table 6, A as the main component
g of P, 0.1 to 3.0 wt% of Pd, and 0.1 to 3.0 wt% of Cu, Au, T as a third element.
An electromagnetic wave shielding body of the present invention in which an electromagnetic wave shielding film 1 made of a three-element Ag alloy material to which any one of i, Cr, Ta, and Mo is added is formed on a surface of a substrate 2 made of various materials. Is an electric field intensity decay rate (dB) in a low frequency range of 100 MHz to a 10 GHz range as compared with a conventional elastomer obtained by blending metal powder or carbon black,
It was confirmed that the radio wave absorbing ability (dB) was excellent and the flexibility (cm) was also excellent. In addition, in a state where the surface is bent at 90 °, no cracks or the like are generated on the surface, and the surface can be bent to a complicated shape (formability).
Was also confirmed to be excellent.

Embodiment 5 Next, in the present invention, an electromagnetic wave shielding film made of an Ag alloy material of at least three elements obtained by the present invention is applied to a portable information terminal device typified by a notebook personal computer or a mobile phone. 1 is formed on the surface of the substrate 2 made of the above-described various materials, and the electromagnetic wave shielding body manufactured and bent, for example, along the outer shape, is directly attached to the electromagnetic wave shielding film 1 exposed on the surface. It can be considered that a part of the human body or some object comes into contact.

In this case, Ag forming the electromagnetic wave shielding body
When the alloy material film is exposed, at least the surface is cut off by contact with the human body or object, or the conductive trace effect is reduced by leaving a scar, or the shielding ability for the specific electromagnetic wave shielding effect is reduced. In order to suppress the occurrence of shaving of the surface portion and the occurrence of a damage mark due to the surface contact, the surface layer portion of the electromagnetic wave shielding body obtained by the present invention is added with Ag, which is a main component, in the surface layer portion. 1 to
3.0 wt% of Pd is added, and 0.1 to 3.0 wt% of Cu, Au, Ti, Cr, T
Ag of three elements to which any one of a and Mo is added
On top of the electromagnetic wave shielding film 1 formed of an alloy material,
The protective film 4 made of a material excellent in corrosion resistance and weather resistance or a material excellent in wear resistance is formed. Thereby, it is possible to prevent a contact flaw caused by some kind of contact with the exposed electromagnetic wave shielding film 1, to suppress a decrease in the electromagnetic wave shielding ability when the protective film 4 is formed, and to further reduce a gap between the substrate 2 and the electromagnetic wave shielding film 1. An electromagnetic wave shield having a laminated structure in which an adhesion-promoting base film 3 is formed as an intermediate base and a protective film 4 is formed thereon (see FIG. 2)
It was confirmed whether or not the electromagnetic wave shielding ability was reduced with respect to the electromagnetic wave shielding effect in the case of the above.

In this case, for example, when the Ag alloy material film is a single layer (single film), when an intermediate base film is formed between the Ag alloy material and the substrate, a metal or metal oxide film is formed, In any of the cases where a protective film was formed on top of the substrate and an intermediate base film was formed between the protective film and the substrate, no remarkable difference in the shielding ability against the electromagnetic wave shielding effect could be confirmed.

Further, for example, pure Ag other than Ag alloy material, A
As described above, a single layer (single film), a multiple layer (two films) having an underlayer formed thereon, pure Ag,
When Al, Cu, and Au are interposed between films of the same or different materials, it has been confirmed that the electromagnetic wave shielding ability is reduced.
Is added in an amount of 0.1 to 3.0 wt%, and C is added as a third element.
Electromagnetic wave shielding film 1 formed on the surface of substrate 2 by a three-element Ag alloy material obtained by adding 0.1 to 3.0 wt% of any one of u, Au, Ti, Cr, Ta, and Mo In the above, among the materials formed on the upper and lower portions, the aforementioned S
i, Ta, Ti, Mo, Cr, Al, ITO, Ir
O ₂ , ZnO ₂ , SiO ₂ , TiO ₂ , Ta ₂ O ₅ , ZrO ₂
The interface is stable against any of the above, for example, without causing a reaction such as oxidation, so that the electromagnetic wave shielding ability, or a conductive loss or a dielectric loss exhibiting effective characteristics for this shielding effect. It turns out there is no effect.

In addition, Pd containing Ag as a main component
3.0 wt%, and further, Cu, Au,
0.1 of any one of Ti, Cr, Ta, and Mo
As a method of forming the electromagnetic wave shielding film 1 made of a three-element Ag alloy material with addition of about 3.0 wt% on the surface of the substrate 2, a sputtering method using an RF or DC power supply, a vacuum deposition method, Although the CVD method can be considered, in each case, a remarkable electromagnetic wave shielding effect as described above was confirmed. As described above, 0.1 to 3.0 wt% of Pd is added to Ag as the main component, and 0.1 to 3.0 wt% of Cu, A as the third element.
A method of forming an electromagnetic wave shielding film 1 made of a three-element Ag alloy material to which one of u, Ti, Cr, Ta, and Mo is added on a surface of a substrate 2 made of various materials As the method, a sputtering method using an RF or DC power supply, a vacuum evaporation method, and a CVD method are preferable.

Natural rubber or chloroprene rubber or E
When forming the electromagnetic wave shielding film 1 made of at least three-element Ag alloy material on the surface of the substrate 1 made of various materials such as PDM, for example, in a sputtering method, a speed standard for forming the film can be considered. The sputtering rate is high, and in the case of the vapor deposition method, the melting point is around 960 ° C., and it does not belong to the high class even if compared with Cu or Au. Since there is no inferiority as compared with the conventional one in terms of performance and vapor deposition, although a film forming method for forming a thin film is arbitrarily selected depending on the material of the substrate, in any case, it is remarkably compared with the conventional one. It was found that there was a significant difference in production by the film forming method.

In a sputtering method or a vapor deposition method studied as a method of forming a thin film on the surface of a substrate,
Regardless of the film formation method, the sputtering method generally has a difference in the density of the obtained thin film when compared with the vapor deposition method. In addition, the vapor deposition method is inferior to the sputtering method in that the denseness of the film is inferior.When forming the electromagnetic wave shielding film by the vapor deposition method, it is said that a thicker film is required than in the case of forming the film by the sputtering method. But
It was found that the three-element Ag alloy material did not reduce the electromagnetic wave shielding effect, and that the same electromagnetic wave shielding effect could be obtained with the same film thickness (nm) by the vapor deposition method and the sputtering method.

[0063]

Since the present invention is constructed as described above, it has the following functions and effects. . In the present invention, Ag is a main component, and 0.1 to 3.0 w
t% of Pd, and 0.1-3.0 wt% of C
Ag consisting of each material composition range to which at least one or more elements are added among u, Au, Ti, Cr, Ta, and Mo
An electromagnetic wave shielding body manufactured by forming an electromagnetic wave shielding film made of an alloy material on the surface of an elastomer material substrate has the same flexibility and shape flexibility (complex shape) as a conventional elastomer made of a compounded metal powder or carbon black, for example. In addition to the above-mentioned elastomer, it is possible to maintain a very high shielding ability against an electromagnetic wave shielding effect, which is very stable as compared with the elastomer.
This makes it possible to obtain a high-quality electromagnetic wave shield that avoids deterioration of the electromagnetic wave shielding ability due to conduction loss, which is useful for maintaining the electromagnetic wave shielding effect for a long time.

[0064] In addition, the electromagnetic wave shield obtained by the present invention can maintain excellent electromagnetic wave shielding characteristics and high visible light transmittance and solar light transmittance over a wide range from a low frequency range of 100 MHz to a 10 GHz range. ,
A higher electromagnetic wave shielding effect can be obtained as compared with conventional elastomers containing, for example, metal powder or carbon black.

[0065] Further, in the present invention, when an electromagnetic wave shielding film is formed using a Ag alloy material on the surface of a substrate made of various materials such as natural rubber, chloroprene rubber, or EPDM, any of sputtering method, vapor deposition method, and even CVD method Even when using the film forming method of the above, regardless of the productivity and the method of forming the thin film, an electromagnetic wave shielding film having a high shielding ability capable of maintaining a stable electromagnetic wave shielding effect over a long period of time is provided on the surface of the substrate. Can be formed.

[0066] In the present invention, for example, an adhesion-promoting base film made of a metal, a metal oxide, or a composite material thereof is formed on the surface of an elastomer material substrate as an intermediate base, and an electromagnetic wave shielding film made of an Ag alloy material is formed thereon. With the electromagnetic wave shielding body having a laminated structure, the adhesion (bonding property) of the electromagnetic wave shielding film to the substrate is more effectively improved, and the bonding without peeling or the like is strengthened. Further, even when a laminated structure in which these materials are formed and laminated on the upper and lower portions of the Ag alloy material has no difference in quality, there is no difference in quality and is equal to or more than a single layer (single film) of the Ag alloy material. An electromagnetic wave shielding body having an electromagnetic wave shielding effect having a further superior difference can be manufactured and provided.

. Alternatively, in the electromagnetic wave shielding body of the present invention, by forming a protective film made of a material excellent in corrosion resistance and weather resistance or a material excellent in wear resistance on the surface of the electromagnetic wave shielding film in the surface layer portion, a human body or an object can be protected. The surface is cut by contact, or the conductive loss effect is reduced by leaving a scar, or there is a concern that the shielding ability for a specific electromagnetic wave shielding effect may be reduced. It is possible to suppress the occurrence of killing marks.

Therefore, according to the present invention, while providing flexibility and shape flexibility (bending followability to a complicated shape),
Ag itself has a high shielding ability against the electromagnetic wave shielding effect, etc. possessed by Ag itself, and furthermore, Ag such as weather resistance, which indicates that the high electromagnetic shielding ability is continuously maintained even in an environment such as high temperature and high humidity. The material stability of itself has been significantly improved,
In addition, the bonding property with the elastomer material substrate is enhanced more effectively by the interposition of the adhesion-promoting base film, and it is useful because it can be widely expected to be applied as an EMC countermeasure material with higher reliability. It is possible to provide an electromagnetic wave shield having high performance.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of an electromagnetic wave shield according to the present invention.

FIG. 2 is a sectional view showing another embodiment of the electromagnetic wave shield of the present invention.

[Explanation of symbols]

 1: electromagnetic wave shielding film 2: substrate 3: adhesion-promoting base film 4: protective film

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] July 16, 2001 (2001.7.1)
6)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Electromagnetic wave shield

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable information terminal device such as a notebook personal computer or a portable telephone, a display device such as an electronic device, a liquid crystal display (LCD) or a plasma display in a transparent opening. Shields electromagnetic waves, infrared rays, and near infrared rays emitted from a display screen such as a panel (PDP). For example, the present invention relates to an electromagnetic wave shield used to prevent radio wave harm caused by an external electromagnetic wave entering an electronic device or the like, and particularly, is attached to the inside of the above-described various electromagnetic wave shields or has an outer shape. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic wave shield excellent in flexibility and flexibility that can be bent and attached along.

[0002]

2. Description of the Related Art In the information society in recent years, as seen in the development of mobile communications such as satellite broadcasting systems and portable information terminal devices, the electromagnetic wave environment has become increasingly diversified and complicated. The evils along with the benefits they bring are becoming apparent. For example, when an external electromagnetic wave from the outside (outside) enters an electronic device or the like and leads to a bad noise,
In addition, there is a concern that electromagnetic waves leaking from portable information terminal devices such as notebook personal computers and mobile phones adversely affect the human body and adversely affect social life. EMC (Electro Magne t ic Com
“Patibility”, that is, electromagnetic compatibility (sometimes called electromagnetic compatibility) is an element that solves various engineering problems caused by electromagnetic waves.

Heretofore, metals have mostly occupied EMC materials for shielding external electromagnetic waves and leakage electromagnetic waves from personal computers and the like (hereinafter the former). Attempts to obtain conductivity by blending metal powder or carbon black with an elastomer material have also been made (hereinafter the latter).

[0004]

However, the former E
In MC materials, products and elements that require EMC technology in recent years have diversified rapidly, and it has become impossible to respond to various functions that are not required only by metal. For example,
Bending followability to complex shapes and filling of unsteady space,
Various problems have occurred, such as the difficulty in applying the method to the problem of weight reduction and corrosion resistance to rust and the like. On the other hand, the latter, which is filled with metal powder, has many disadvantages such as a change with time mainly due to metal oxidation and a loss of mechanical properties such as elasticity and strength of the elastomer itself. It is hard to say. Although elastomers filled with carbon black have been diversified into conductive rollers, rubber contacts, and the like, they are hardly used as EMC materials because of the limited conductivity obtained. As described above, the conventional electromagnetic wave shield has problems in bending followability to complicated shapes, corrosion resistance, and weather resistance and wear resistance, respectively. ) Is not possible.

[0005] The present invention has been made in view of such a conventional situation, and a purpose thereof is to provide an electromagnetic wave shielding film made of an Ag alloy material on a surface of a substrate made of an elastomer material. It is an electromagnetic wave shield with excellent properties,
Flexibility, shape flexibility (bendability to complicated shapes)
With a wide range of applications mainly as an EMC countermeasure material,
Further, the material stability such as weather resistance, which is that high electromagnetic wave shielding ability is continuously maintained even in an environment such as high temperature and high humidity, is remarkably improved, and the bonding property with the elastomer material substrate ( Adhesion) is more effectively strengthened,
An object of the present invention is to provide an electromagnetic wave shield capable of obtaining higher reliability.

[0006]

[Means for achieving the object] To achieve the object,
In the present invention, the electromagnetic wave shielding effect is high and chemically stable,
In addition, an electromagnetic wave shielding film made of an Ag alloy material containing Ag as a main component, Pd, and at least one or more of Cu, Au, Ti, Cr, Ta, and Mo that can be easily manufactured. Is formed on the surface of a conductive elastomer material substrate. here,
The thickness of the electromagnetic wave shielding film is preferably, for example, about 10 to 500 nm in consideration of, for example, bending followability to a complicated shape. Further, the electromagnetic wave shielding film, a single film according to the use of the electromagnetic wave shield,
Alternatively, by forming a multilayer film of two or more films on the surface of the substrate, it is stable in temperature and chemical stability, and can be applied to various uses. Further, the electromagnetic wave shielding film,
Pd is added within the range of 0.1 to 3.0 wt%, and C is further added.
It is formed from an Ag alloy material to which at least one or more of u, Au, Ti, Cr, Ta, and Mo is added in a range of 0.1 to 3.0 wt%. Examples of the elastomer material include natural rubber, chloroprene rubber, and EPDM (rubber-like terpolymer of ethylene / propylene and diene).

In the present invention, the Ag alloy material is a vapor deposition material or a sputtering target material, and the electromagnetic wave shielding film is formed on the surface of the substrate by a film forming process such as a vapor deposition method or a sputtering method.

[0008] In the present invention, on the above-mentioned electromagnetic wave shielding film,
A protective film made of a material having excellent corrosion resistance and weather resistance, or a protective film made of a material having excellent wear resistance is formed.

Further, in the present invention, an adhesion promoting base film for promoting adhesion between the substrate and the electromagnetic wave shielding film is formed between the substrate and the electromagnetic wave shielding film. In addition, as a material of the adhesion promoting base film, ITO (In oxide and Sn oxide) is used.
Composite oxide), IrO ₂ , ZnO ₂ , SiO ₂ , Ti
At least one selected from O ₂ , Ta ₂ O ₅ , and ZrO ₂ ;
Alternatively, a metal oxide material composed of two or more kinds containing these as main components is preferable. Or Si, Ta, Ti, M
It is preferable to use at least one selected from o, Cr, and Al, or a material composed of two or more of these as main components.

[0010]

Embodiments of the present invention will be described. FIG. 1 is a cross-sectional view showing an embodiment of the electromagnetic wave shield of the present invention, in which an electromagnetic wave shield film 1 made of an Ag alloy material described later is adhered to a surface of a substrate 2 made of at least a conductive elastomer material. It is formed by lamination with the ground film 3 interposed.

[0011] In the present invention, the self-diffusion energy for the heat held by Ag itself is relaxed to suppress the phenomenon of clouding due to surface diffusion which is likely to occur when heated to at least about 100 ° C. is important. That is, Ag is known to be the material having the best electromagnetic wave shielding ability. However, for example, a problem that self-diffusion energy for heat is active is likely to occur. For this reason, when heat of about 100 ° C. is applied even temporarily, a diffusion phenomenon occurs on the surface, and the Ag itself loses its gloss and becomes cloudy. In other words, the characteristics of Ag itself, which is superior in electromagnetic wave shielding performance, are reduced.

Therefore, Ag has a very good thermal conductivity and has a characteristic of easily absorbing and saturating heat in atomic units. Therefore, Ag is required to reduce thermal conductivity and to suppress active movement between atoms. An experiment was carried out by adding Pd, which is an atom forming a solid solution with respect to Ag, in a composition range of 0.1 to 4.0% by weight. First, each of sputtering of Ag and Pd is mounted on a sputtering apparatus, and the discharge amounts of Ag and Pd are controlled with a specific RF power to obtain Ar and Pd.
The (argon) gas is arbitrarily set between 0.1 and 3.0 Pa, and the two materials are sputtered simultaneously. In other words, the amount of addition of several types of Pd is changed by simultaneous sputtering, and Ag is added.
An alloy material film was formed. At this time, the test specimen
Using a quartz substrate of 100 mm × 100 mm × 1.1 mm , the substrate temperature during the sputtering process is normal temperature (around 25 ° C.), and only Ar gas is used as a sputtering gas.
The film was formed with a film thickness of 20 nm in a high vacuum atmosphere of a ultimate vacuum degree of 3 × 10E-6 Pa. The reason for forming a film in a high vacuum atmosphere is to suppress the impurity gas and the like from being dependent on the grain boundaries of the alloy film and to confirm the original physical properties of the material by forming a dense film. That's why.

An Ag alloy material thin film containing Ag formed as a main component and Pd added with several kinds of material compositions thereon is placed on a hot plate in the air and left for about 2 hours to reduce the white turbidity. A heating test was conducted to observe the presence / absence and the temperature at which clouding started. At this time, the heating method of the hot plate is a resistance heating method, and the heating temperature is 2
The heating rate was set to 50 ° C. and the heating rate was set to 20 ° C./min. Table 1 shows the test results.

[0014]

[Table 1]

In general, it is well known that the addition of Pd improves the lack of weather resistance in a high-temperature and high-humidity (humid) environment possessed by Ag. No significant difference as shown in Table 1 can be confirmed with respect to the surface diffusion resistance of No. 1, and a remarkable superiority can be confirmed as compared with Ag with respect to the reduction of clouding due to the addition of Pd. Did not. Further, since it was confirmed that the electromagnetic wave shielding ability was reduced by about 2 to 3% after heating as compared to before heating, the effect of preventing surface diffusion due to the addition of Pd could not be confirmed.

Embodiment 1 In the present invention, first, Ag, which is a main component, is added in an amount of 0.1 to 0.1%.
3.0 wt% Pd is added, and Cu, Au, Ti, C
At least one element of r, Ta, and Mo was added to form an Ag alloy material thin film composed of at least three elements, and suppression of surface diffusion due to heat was studied. At this time, the addition amount of at least one element among Cu, Au, Ti, Cr, Ta, and Mo is 0.1 to
3.0 wt%. As a method of forming a thin film, one selected from a sputtering target material of Ag and Pd, and further, any one of Cu, Au, Ti, Cr, Ta, and Mo is mounted on an RF magnetron sputtering apparatus. By simultaneously sputtering three metal elements, a thin film made of a three-element Ag alloy material was formed. At this time, the test substrate was 100 mm x 100 mm x 1.
Using a 1 mm quartz substrate, the substrate temperature during the sputtering process is room temperature (around 25 ° C.), only Ar (argon) gas is used as the sputtering gas, and the ultimate vacuum degree is 3 × 10E-6 Pa. The film was formed in a high vacuum atmosphere with the same thickness of 20 nm as that of the above-described Ag-Pd two-element alloy.

The test sample in this method contains A as the main component.
g, Pd is added in an amount of 0.1 to 3.0 wt%, and Cu,
A three-element Ag alloy material thin film obtained by adding 0.1 to 3.0 wt% of any one of Au, Ti, Cr, Ta and Mo is directly formed on the surface of a quartz substrate with a thickness of 20 nm. In the same manner as described above, a heating test was performed in which the sample was placed on a hot plate maintained at a heating temperature of 250 ° C. and left for 2 hours, and the presence or absence of cloudiness and the temperature at which clouding was started were observed. The test results are shown in Tables 2 and 3.

[0018]

[Table 2]

[0019]

[Table 3]

Then, Pd is added to Ag or Ag by 0.1 to 0.1%.
In the case of the two-element Ag-Pd alloy material added with 4.0 wt%, as is apparent from Table 1 above, the surface of the film becomes clouded and the electromagnetic wave shielding ability is reduced to a considerable extent. Ag is used as a main component and Pd is set to 0.1 to 3.0.
wt%, and Cu, Au, Ti,
Any one of Cr, Ta, and Mo is used in 0.1 to 3.
As can be seen from Tables 2 and 3, in the three-element Ag alloy material to which 0 wt% was added, no clouding phenomenon or reduction in electromagnetic wave shielding ability was observed in all the material composition ranges.

Then, the quartz substrate on which the Ag alloy material films formed in various material composition ranges subjected to the heating test at 250 ° C. are further left on a hot plate heated to 400 ° C. for 2 hours. In any case, no clouding or reduction in electromagnetic wave shielding ability was observed in any of the material composition ranges.

In addition, Cu, Au, T
Any one of i, Cr, Ta, and Mo is 0.1 to
As described above, a test sample in which a two-element Ag alloy material thin film to which 3.0 wt% was added was directly formed on a quartz substrate with a thickness of 15 nm by a sputtering method at the same time was heated at both 250 ° C. and 400 ° C. When a heating test was performed to observe changes over time, it was confirmed that all the films became cloudy and the electromagnetic wave shielding ability was reduced.

As described above, the content of Ag as the main component is 0.1 to
3.0 wt% of Pd is added, and 0.1 to 3.0 wt% of Cu, Au, Ti, Cr, T
By using a three-element Ag alloy material obtained by adding any one of a and Mo, a significant improvement in heat resistance is recognized, and furthermore, the electromagnetic wave shielding effect of Ag itself is reduced. It has been found that the high shielding ability can be maintained without deteriorating.

Example 2 In the present invention, when a heating test was performed on the electromagnetic wave shielding film 1 made of an Ag alloy material having various material composition ranges having a high heat resistance, a slight peeling was observed at the end of the thin film. Was observed, and it was confirmed that the adhesion was at least weak to a substrate made of a specific material. Therefore, the adhesion between the substrate and the electromagnetic wave shielding film 1 made of a three-element Ag alloy material of each material composition range was determined. investigated.

Therefore, in the present invention, in order to confirm the adhesion of the electromagnetic wave shielding film 1 made of the three-element Ag alloy material in each of the above-described material composition ranges, at least a conductive elastomer material, in particular, various materials described below. Substrate 2 consisting of
After forming a thin film having a thickness of 15 nm directly on the surface of the substrate by a three-element simultaneous sputtering method as in the past, a test for confirming adhesion by a peel test method was attempted. Then
Since it was confirmed that the adhesiveness was not necessarily high for any substrate 2 made of various materials, the electromagnetic wave shielding film 1 made of a three-element Ag alloy material consisting of various material compositions and a substrate 2 made of various materials was used. In the meantime, the adhesion was further studied by forming a specific adhesion promoting base film 3 which promotes the adhesion between them as an intermediate base.

As an elastomer material for forming the substrate 2,
Natural rubber, chloroprene rubber, EPDM (rubber-like terpolymer of ethylene / propylene and diene) and the like can be mentioned.

The material of the adhesion promoting base film 3 is materially stable with respect to the substrate 2 made of oxygen or the above-mentioned various materials. Further, the material of the electromagnetic wave shielding film 1 made of an Ag alloy material of at least three elements is used. Considering that the adhesiveness is good, Si, Ta, Ti, Mo, Cr, Al, ITO (composite oxide of In oxide and Sn oxide), IrO ₂ , ZnO ,
After forming SiO ₂ , TiO ₂ , Ta ₂ O ₅ , ZrO _2, etc. on the surface of the substrate 2 made of various materials by the RF sputtering method, various kinds of the three-element simultaneous sputtering method are performed thereon as in the past. When an electromagnetic wave shielding film 1 made of a three-element Ag alloy material having various material composition ranges was formed and a peel test was performed, natural rubber or chloroprene rubber was obtained by interposing an adhesion-promoting underlayer 3 as an intermediate substrate. Or E
It has been found that the adhesion of the electromagnetic wave shielding film 1 to the substrate 2 made of various materials such as PDM is greatly improved, and the bondability with the substrate 2 made of various materials is further effectively enhanced.

In this case, the base film 3 for promoting adhesion of the substrate 2 made of various materials is made of Si, Ta, Ti, Mo,
Cr, Al, ITO, ZnO, SiO 2, TiO 2, Ta
₂ O ₅ and ZrO ₂ are desirable, but when examined on the surface of the substrate 2 made of various materials, ITO, ZnO , Si
A metal oxide thin film such as O ₂ , TiO ₂ , Ta ₂ O ₅ , and ZrO ₂ is desirable. The reason is that the substrate 2 made of natural rubber, chloroprene rubber, or EPDM generates a very large amount of gas when it has a specific purity or material. Further, the metal reacts strongly with the generated gas. Also, contact to adhere the Ag alloy
In such a case, it is difficult to examine the suitability because it is highly likely that a reaction passivation film (for example, an oxide film or the like) is formed on the interface .

Also, the adhesion promoting base film 3 is formed by sputtering.
Is formed on the surface of the substrate 2, when the sputtering method is performed in a vacuum atmosphere, the substrate made of natural rubber, chloroprene rubber, or EPDM is switched during switching from the atmosphere to a vacuum to evacuate the atmosphere in the apparatus. In the case of (1), a gas is generated.
This is because the interface with the substrate tends to be unstable.

An important issue when studying the adhesion-promoting base film 3 is whether or not the film can be easily formed. For example, Si, Ta, Ti, Mo, C
Metal films such as r and Al can be formed by vapor deposition, sputtering, C
Since the film can be formed by any of the VD method and the ion plating method, it can be interlocked with a method of forming at least a three-element Ag alloy material film.
General utility can be considered high.

In addition, ITO, ZnO , SiO ₂ , TiO ₂ ,
A metal oxide thin film such as Ta ₂ O ₅ or ZrO ₂ can be easily formed by a vapor deposition method, a sputtering method, or an ion plating method. For example , an AR film formed on a CRT monitor, a liquid crystal display device, or the like can be used. For the anti-reflection) coating, the adhesion promoting base film 3 is formed on the surface of the substrate 2 made of various materials. By forming an AR coating on top of the thickness of about 1.2 nm, a remarkable effect can be confirmed as a shielding effect against electromagnetic waves, which has been a problem in cathode ray tube monitors (CRTs) and liquid crystal display devices. did it.

Embodiment 3 As the material of the electromagnetic wave shielding film 1, Ag is, as described above, surface diffusion, in the air, or when the substrate 2 made of natural rubber, chloroprene rubber, or EPDM is used. Because of the strong discoloration effect due to the gas and the like emitted from 2, it has been determined that the versatility is not high and has been set as an issue.

Therefore, in the present invention, 0.1 to 3.0 wt% of Pd is added with Ag as a main component, which has been confirmed to have corrosion resistance and durability against heat resistance and discoloration, and Cu, Au,
0.1 of any one of Ti, Cr, Ta, and Mo
A study was conducted to determine what shielding effect can be obtained with respect to the electromagnetic wave shielding by the three-element Ag alloy material added by about 3.0 wt%.

As a test sample of this method, the three-element Ag alloy described above was applied to the surface of all substrates 2 made of various materials such as natural rubber, chloroprene rubber, or EPDM by a three-element simultaneous sputtering method as before. An electromagnetic wave shielding film 1 made of a material was formed, and the film was measured by a KEC method (a device devised by Kansai Electronics Promotion Center) to confirm the electromagnetic wave shielding ability. Here, a laminated structure in which the electromagnetic wave shielding film 1 made of an Ag alloy material of each material composition range is directly formed on all the substrates 2 made of the various materials described above, and an intermediate base made of, for example, ITO, ZnO , SiO A laminated structure in which an adhesion-promoting base film 3 made of ₂ or the like is formed on the surface of the substrate 2 and an electromagnetic wave shielding film 1 is formed thereon (see FIG. 1).
The analysis of the electromagnetic wave shielding ability was carried out at the same time. Furthermore, it was also checked whether there was any difference between the Ag alloy material itself and the intermediate underlayer formed, and the Ag alloy material thin film formed on the intermediate underlayer.

Then, for the electromagnetic wave shielding effect, Au,
It can be confirmed that there is a significant difference as compared with the electromagnetic wave shielding film made of a material such as Al, Cu, and Ag. In the case of an Ag alloy material composed of at least three elements, the electromagnetic wave could not be obtained with the material. It was confirmed that it was possible to obtain a high electromagnetic wave shielding ability with respect to the shielding effect. Also, for example, at least about 30 dB in a wide range from a low frequency range of 100 MHz to a 1 GHz range.
It was confirmed that the sheet exhibited an electromagnetic wave shielding characteristic of (the intensity of the electromagnetic wave was about 0.1% of the original attenuation).
In addition, ITO, ZnO , Si
In the case of an electromagnetic wave shielding body having a laminated structure in which an adhesion promoting base film made of O ₂ or the like is formed and an electromagnetic wave shielding film 1 made of at least three elements of an Ag alloy material is formed thereon, a single layer (single film) electromagnetic wave is formed. No decrease in shielding ability against electromagnetic wave shielding effect was observed even when compared with the case of shielding film, single layer (single film)
It was confirmed that a high shielding ability was maintained as in the case of the electromagnetic wave shielding film of (1).

In this case, preferably, ITO and ZnO are used.
By providing such a conductive oxide as the adhesion-promoting base film 3 between the substrate 2 and the electromagnetic wave shielding film 1, it can be confirmed that the electromagnetic wave shielding effect is higher than at least when SiO ₂ is provided. Was.

In this case, it is desirable that the material of the adhesion promoting base film 3 has a lower resistance . at least
It was confirmed that ITO was more effective in obtaining a higher electromagnetic wave shielding ability than ZnO . The reason for this is that when an Ag alloy material of at least three elements and a specific intermediate base film are provided between the Ag alloy material thin film and the substrate for the purpose of shielding electromagnetic waves, and an electric field is applied to the multilayer film itself, A conduction current flows inside the multilayer film, and this electric energy is converted into heat energy. Further, a heat generation mechanism that converts the heat energy into heat energy is mainly caused by absorption of electromagnetic waves and conduction loss. Because it happens.

Further, since the effect of this conduction loss is high depending on the amount of the conduction current flowing, the lower the resistance of the electromagnetic wave shielding film, the more significant the difference becomes. However, Ag or A
For l and Cu, the movement of atoms of the material itself, that is, a heat generation mechanism that is a conversion from electric energy to heat energy due to the electromigration phenomenon is attenuated over time, so that at least a specific film thickness is provided. Although the damping effect has been reduced by this, Ag of the present invention is used as a main component, and Pd is added in an amount of 0.1 to 3.0 wt%. Further, any one of Cu, Au, Ti, Cr, Ta, and Mo It has been found that in a three-element Ag alloy material to which 0.1 to 3.0 wt% is added, the damping action is remarkably reduced because the movement of the film itself between metal atoms is not active.

In addition, here, the conductivity represented by ITO and ZnO is
It is not an electrically conductive oxide but is, for example, an insulating material.
SiO_Two, TiO_Two, Ta_TwoO_Five, ZrO_TwoSuch as dielectric
When an intermediate base is interposed between the Ag alloy material and the substrate
In the case, the effect of the high conduction loss possessed by the Ag alloy material
In addition, electromagnetic wave energy at high frequencies called dielectric loss
The effect of the absorption of the
In order to obtain a high magnetic wave shielding effect,
Conductive as metal oxide film interposed as ground film
There is no need to limit the material. Ag at least as a main component
Then, Pd is added in an amount of 0.1 to 3.0 wt%, and Cu and A are further added.
u, Ti, Cr, Ta, Mo
Ag alloy material of three elements added by 0.1 to 3.0 wt%
In the electromagnetic wave shielding film 1 formed by the material, S
Metal film of i, Ta, Ti, Mo, Cr, Al, etc.
Is ITO, IrO _Two,ZnO, SiO_Two, TiO_Two, Ta_Two
O_Five, ZrO_TwoOf metal oxide films and metal composite oxides
Ag alloy material film and substrate
If it is interposed as an intermediate base film,
No difference, high electromagnetic wave shielding effect in any case
The result was confirmed.

Example 4 Further, as an Ag alloy material which has so far been excellent in corrosion resistance and heat resistance, a two-element Ag-Pd alloy obtained by adding 1 to 3 wt% of Pd to Ag, or a 1 to 1 element in Ag 10w
Ag-Au alloys to which t% Au is added are widely known. However, even if an alloy film formed using any of the Ag-Pd alloy and the Ag-Au alloy is used, high-temperature, high-humidity (high humidity) When the weather resistance test was performed in an environment, black spots were observed.

Therefore, when the black spots were observed with an optical microscope and observed, the black spots reached the solid solution limit of the H ₂ melting action of Pd, and turned black to cause an excitation reaction, which caused the black spots to become protruded. Because of this, it was found that stability was lacking for long-term reliability in high humidity in a rainy season or in localization with high humidity.

It is well known that Ag and Au are stable alloys in which all the components are solid-solved. However, this Ag—Au alloy film has resistance to halogen elements such as chlorine.
It was found that air was mixed during the weather resistance test due to lack of abundance, and that such black spots were obtained by atomically bonding to chlorine or iodine contained in the air.

Also, as shown in Table 1 above, the binary alloy of Ag-Pd does not have high heat resistance, as shown in Table 1 above, because of its high stability against heat rays concentrated from sunlight. Known problems.

Therefore, in the present invention, Pd is contained in a content of 0.1 to 3.0 mainly containing Ag which has been confirmed to have high heat resistance.
wt%, Cu, Au, Ti, Cr, Ta, M
a three-element Ag alloy material obtained by adding 0.1 to 3.0 wt% of any one of the above-described materials to a temperature of 90 ° C. and a humidity of 90 ° C.
An experiment was conducted to find out what results can be obtained with respect to the weather resistance in a high-temperature, high-humidity (humidity) environment in comparison with an Ag-Pd alloy having at least two elements.

In this method, as described above, natural rubber or chloroprene rubber or E
On the surface of all substrates 1 made of various materials such as PDM,
An electromagnetic wave shielding film 1 made of a three-element Ag alloy material of each of the above-described material composition ranges is formed, and it is checked whether there is any change with time in a high-temperature and high-humidity atmosphere at a temperature of 90 ° C. and a humidity of 90%. saw. At this time, all the substrates 2 made of various materials are used.
And Pd containing 0.1 to 3.0 wt% with Ag as a main component.
%, And further, a directly formed three-element Ag alloy material obtained by adding 0.1 to 3.0 wt% of any one of Cu, Au, Ti, Cr, Ta, and Mo. _{ITO, ZnO, ZnO -Al 2 O} 3 composite oxide, SiO ₂
A weather resistance test was conducted simultaneously with those obtained by forming the above.
At the same time, it was also checked whether there was any difference between the case where the Ag alloy material itself and the above-mentioned adhesion promoting base film 3 were formed as an intermediate base film and the Ag alloy material was formed on the base film.

Then, Pd is made 0.1 with Ag as the main component.
To 3.0 wt%, and further, Cu, Au, Ti, C
Any one of r, Ta, and Mo is 0.1 to 3.0.
Even in the case of a single layer (single film) of an electromagnetic wave shielding film formed of a three-element Ag alloy material added by wt%, as shown in FIG. Even when the electromagnetic wave shield is formed by using the adhesion-promoting base film 3 made of a material selected from ITO, ZnO , and SiO _{2 as the} intermediate base, compared with the single-layer (single-layer) Ag alloy material film It was confirmed that the weather resistance was high.

As a result, Pd containing Ag as a main component
Of 0.1 to 3.0 wt%, and further, Cu, Au,
0.1 of any one of Ti, Cr, Ta, and Mo
In the case of a three-element Ag alloy material film with an addition of up to 3.0 wt%, even if an oxide is arbitrarily formed between the Ag alloy material film and the substrate as an upper film, the heat resistance and the weather resistance are not dependent on the underlayer. It has been confirmed that it has high electromagnetic wave shielding ability, and that it is highly useful as an electromagnetic wave shielding body for recent EMC countermeasure materials, such as a wide range of applications.

Further, in the present invention, 0.1 to 3.0 wt% of Pd containing Ag as a main component is added, and Cu, Au, Ti,
In order to confirm the chemical stability of an Ag alloy material film composed of three or more elements in which at least one element of Cr, Ta, and Mo is added in a total of 0.1 to 3.0 wt% in total. Using a test sample in which an electromagnetic wave shielding film 1 having a thickness of 15 nm was formed on the surface of a substrate 2 made of various materials such as natural rubber, chloroprene rubber, or EPDM by a ternary simultaneous sputtering method as before, Temperature 90 ° C,
It was left for 24 hours in a high-temperature, high-humidity (humid) environment at a humidity of 90%, and its appearance and changes over time in electromagnetic wave shielding characteristics were observed. Tables 4 and 5 show the test results.

[0049]

[Table 4]

[0050]

[Table 5]

As is clear from Tables 4 and 5, since no change with time was observed in the material even after standing for 24 hours, it was formed on the surface of a substrate made of various materials such as natural rubber, chloroprene rubber or EPDM. Ag is used as a main component, and Pd is added in an amount of 0.1 to 3.0 wt%.
The electromagnetic wave shielding ability of a three-element Ag alloy material film formed by adding 0.1 to 3.0 wt% of any one of u, Ti, Cr, Ta, and Mo was determined by the KEC method (Kansai Electron Promotion Center devised Device) and observed.
In a wide range from a low frequency range of 1 MHz to a 1 GHz range,
No reduction in electromagnetic wave shielding ability was confirmed. Like this
The electromagnetic wave shielding film 1 made of a three-element Ag alloy material containing Ag as a main component has high chemical stability and is not limited to all substrates 2 made of various materials such as natural rubber, chloroprene rubber, or EPDM. I found out.

Separately from this, the electric field intensity attenuation rate (dB) from the low frequency range of 100 MHz to the 1 GHz range by the near-field measurement of the electromagnetic wave shield obtained by the present invention is 20 dB.
Therefore, the radio wave absorption capability (d from 100 MHz low frequency range to 1 GHz range) is required.
B) The flexibility (cm) was measured. In addition, about flexibility measurement, it is an appropriate size (for example, 10 mm width strip shape).
Test sample cut into pieces (electromagnetic wave shield obtained by the present invention)
The index is obtained by gradually taking out the test sample from the end of the bench while holding down the end of the test bench, and measuring the length of the test sample on the bench at the time when the hanging part becomes just 90 °. did. Table 6 shows the measurement results. The near field is
When the wavelength is λ in radio wave engineering, it means an electric field at a distance within λ / 6 wavelength. The electric field intensity attenuation rate is an index of the electromagnetic wave shielding ability, and the electromagnetic wave shielding ability of a material is measured by an automated measuring device that makes the measurement principle the same.

Comparative Example As a comparative example, 100 parts of a vinyl group-containing polydimerylsiloxane having an average degree of polymerization of about 6,000 and containing 0.06% of a merylvinylsiloxane unit, which is a dimethylvinylcytyl group, at both terminals was added to conductive carbon. Furnace black “$ 3030B” (manufactured by Mitsubishi Chemical Corporation) 40 as black
Parts and 10 parts of diatomaceous earth were charged into a kneader and kneaded, and then 2,5- dimethyl- 2,5-di- as a crosslinking agent.
1.5 parts of t-butyl peroxyhexane was added to obtain a uniform silicone rubber compound. Then, a test sample was prepared by forming a rubber plate having a thickness of 1 mm and a side of 100 mm on each side by press molding the compound at 170 ° C. for 10 minutes and vulcanizing at 200 ° C. for 4 hours . In addition, as a sample for measuring the electromagnetic wave shielding ability , a thickness of 7.
A rubber plate having a size of 5 mm and a side of 50 mm was prepared by the same method and procedure as described above.

[0054]

[Table 6]

As is apparent from Table 6, A as the main component
g of P, 0.1 to 3.0 wt% of Pd, and 0.1 to 3.0 wt% of Cu, Au, T as a third element.
An electromagnetic wave shielding body of the present invention in which an electromagnetic wave shielding film 1 made of a three-element Ag alloy material to which any one of i, Cr, Ta, and Mo is added is formed on a surface of a substrate 2 made of various materials. Is excellent in electric field intensity attenuation rate (dB) and radio wave shielding ability (dB) in a low frequency range of 100 MHz to 1 GHz range, and is more flexible than a conventional elastomer mixed with metal powder or carbon black. It was also confirmed that the properties (cm) were excellent. In addition, in a state where the surface is bent at 90 °, no cracks or the like are generated on the surface, and the surface can be bent to a complicated shape (formability).
Was also confirmed to be excellent.

Embodiment 5 Next, in the present invention, an electromagnetic wave shielding film made of an Ag alloy material of at least three elements obtained by the present invention is applied to a portable information terminal device typified by a notebook personal computer or a mobile phone. 1 is formed on the surface of the substrate 2 made of the above-described various materials, and the electromagnetic wave shielding body manufactured and bent, for example, along the outer shape, is directly attached to the electromagnetic wave shielding film 1 exposed on the surface. It can be considered that a part of the human body or some object comes into contact.

In this case, Ag forming the electromagnetic wave shielding body
When the alloy material film is exposed, at least the surface is cut off by contact with the human body or object, or the conductive trace effect is reduced by leaving a scar, or the shielding ability for the specific electromagnetic wave shielding effect is reduced. In order to suppress the occurrence of shaving of the surface portion and the occurrence of a damage mark due to the surface contact, the surface layer portion of the electromagnetic wave shielding body obtained by the present invention is added with Ag, which is a main component, in the surface layer portion. 1 to
3.0 wt% of Pd is added, and 0.1 to 3.0 wt% of Cu, Au, Ti, Cr, T
Ag of three elements to which any one of a and Mo is added
On top of the electromagnetic wave shielding film 1 formed of an alloy material,
The protective film 4 made of a material excellent in corrosion resistance and weather resistance or a material excellent in wear resistance is formed. Thereby, it is possible to prevent a contact flaw caused by some kind of contact with the exposed electromagnetic wave shielding film 1, to suppress a decrease in the electromagnetic wave shielding ability when the protective film 4 is formed, and to further reduce a gap between the substrate 2 and the electromagnetic wave shielding film 1. An electromagnetic wave shield having a laminated structure in which an adhesion-promoting base film 3 is formed as an intermediate base and a protective film 4 is formed thereon (see FIG. 2)
It was confirmed whether or not the electromagnetic wave shielding ability was reduced with respect to the electromagnetic wave shielding effect in the case of the above.

In this case, for example, when the Ag alloy material film is a single layer (single film), when an intermediate base film is formed between the Ag alloy material and the substrate, a metal or metal oxide film is formed, In any of the cases where a protective film was formed on top of the substrate and an intermediate base film was formed between the protective film and the substrate, no remarkable difference in the shielding ability against the electromagnetic wave shielding effect could be confirmed.

Further, for example, pure Ag other than Ag alloy material, A
As described above, a single layer (single film), a multiple layer (two films) having an underlayer formed thereon, pure Ag,
When Al, Cu, and Au are interposed between films of the same or different materials, it has been confirmed that the electromagnetic wave shielding ability is reduced.
Is added in an amount of 0.1 to 3.0 wt%, and C is added as a third element.
Electromagnetic wave shielding film 1 formed on the surface of substrate 2 by a three-element Ag alloy material obtained by adding 0.1 to 3.0 wt% of any one of u, Au, Ti, Cr, Ta, and Mo In the above, among the materials formed on the upper and lower portions, the aforementioned S
i, Ta, Ti, Mo, Cr, Al, ITO, Ir
Since the interface is stable to any of O ₂ , ZnO , SiO ₂ , TiO ₂ , Ta ₂ O ₅ , and ZrO ₂ without causing a reaction such as oxidation, the electromagnetic wave shielding ability or the shielding effect is reduced. It has been found that there is no effect on the conductive loss or the dielectric loss that exhibits the effective characteristics for this.

In addition, Pd containing Ag as a main component
3.0 wt%, and further, Cu, Au,
0.1 of any one of Ti, Cr, Ta, and Mo
As a method of forming the electromagnetic wave shielding film 1 made of a three-element Ag alloy material with addition of about 3.0 wt% on the surface of the substrate 2, a sputtering method using an RF or DC power supply, a vacuum deposition method, Although the CVD method can be considered, in each case, a remarkable electromagnetic wave shielding effect as described above was confirmed. As described above, 0.1 to 3.0 wt% of Pd is added to Ag as the main component, and 0.1 to 3.0 wt% of Cu, A as the third element.
A method of forming an electromagnetic wave shielding film 1 made of a three-element Ag alloy material to which one of u, Ti, Cr, Ta, and Mo is added on a surface of a substrate 2 made of various materials As the method, a sputtering method using an RF or DC power supply, a vacuum evaporation method, and a CVD method are preferable.

Natural rubber or chloroprene rubber or E
When forming the electromagnetic wave shielding film 1 made of at least three-element Ag alloy material on the surface of the substrate 1 made of various materials such as PDM, for example, in a sputtering method, a speed standard for forming the film can be considered. The sputtering rate is high, and in the case of the vapor deposition method, the melting point is around 960 ° C., and it does not belong to the high class even if compared with Cu or Au. Since there is no inferiority as compared with the conventional one in terms of performance and vapor deposition, although a film forming method for forming a thin film is arbitrarily selected depending on the material of the substrate, in any case, it is remarkably compared with the conventional one. It was found that there was a significant difference in production by the film forming method.

In a sputtering method or a vapor deposition method studied as a method of forming a thin film on the surface of a substrate,
Regardless of the film formation method, the sputtering method generally has a difference in the density of the obtained thin film when compared with the vapor deposition method. In addition, the vapor deposition method is inferior to the sputtering method in that the denseness of the film is inferior.When forming the electromagnetic wave shielding film by the vapor deposition method, it is said that a thicker film is required than in the case of forming the film by the sputtering method. But
It was found that the three-element Ag alloy material did not reduce the electromagnetic wave shielding effect, and that the same electromagnetic wave shielding effect could be obtained with the same film thickness (nm) by the vapor deposition method and the sputtering method.

[0063]

Since the present invention is constructed as described above, it has the following functions and effects. . In the present invention, Ag is a main component, and 0.1 to 3.0 w
t% of Pd, and 0.1-3.0 wt% of C
Ag consisting of each material composition range to which at least one or more elements are added among u, Au, Ti, Cr, Ta, and Mo
An electromagnetic wave shielding body manufactured by forming an electromagnetic wave shielding film made of an alloy material on the surface of an elastomer material substrate has the same flexibility and shape flexibility (complex shape) as a conventional elastomer made of a compounded metal powder or carbon black, for example. In addition to the above-mentioned elastomer, it is possible to maintain a very high shielding ability against an electromagnetic wave shielding effect, which is very stable as compared with the elastomer.
This makes it possible to obtain a high-quality electromagnetic wave shield that avoids deterioration of the electromagnetic wave shielding ability due to conduction loss, which is useful for maintaining the electromagnetic wave shielding effect for a long time.

[0064] In addition, the electromagnetic wave shield obtained according to the present invention can maintain excellent electromagnetic wave shielding characteristics over a wide range from a low frequency range of 100 MHz to a 1 GHz range, so that conventional metal powder or carbon black can be used. A higher electromagnetic wave shielding effect can be obtained as compared with the elastomer obtained by blending.

[0065] Further, in the present invention, when an electromagnetic wave shielding film is formed using a Ag alloy material on the surface of a substrate made of various materials such as natural rubber, chloroprene rubber, or EPDM, any of sputtering method, vapor deposition method, and even CVD method Even when using the film forming method of the above, regardless of the productivity and the method of forming the thin film, an electromagnetic wave shielding film having a high shielding ability capable of maintaining a stable electromagnetic wave shielding effect over a long period of time is provided on the surface of the substrate. Can be formed.

[0066] In the present invention, for example, an adhesion-promoting base film made of a metal, a metal oxide, or a composite material thereof is formed on the surface of an elastomer material substrate as an intermediate base, and an electromagnetic wave shielding film made of an Ag alloy material is formed thereon. With the electromagnetic wave shielding body having a laminated structure, the adhesion (bonding property) of the electromagnetic wave shielding film to the substrate is more effectively improved, and the bonding without peeling or the like is strengthened. Further, even when a laminated structure in which these materials are formed and laminated on the upper and lower portions of the Ag alloy material has no difference in quality, there is no difference in quality and is equal to or more than a single layer (single film) of the Ag alloy material. An electromagnetic wave shielding body having an electromagnetic wave shielding effect having a further superior difference can be manufactured and provided.

. Alternatively, in the electromagnetic wave shielding body of the present invention, by forming a protective film made of a material excellent in corrosion resistance and weather resistance or a material excellent in wear resistance on the surface of the electromagnetic wave shielding film in the surface layer portion, a human body or an object can be protected. The surface is cut by contact, or the conductive loss effect is reduced by leaving a scar, or there is a concern that the shielding ability for a specific electromagnetic wave shielding effect may be reduced. It is possible to suppress the occurrence of killing marks.

Therefore, according to the present invention, while providing flexibility and shape flexibility (bending followability to a complicated shape),
Ag itself has a high shielding ability against the electromagnetic wave shielding effect, etc. possessed by Ag itself, and furthermore, Ag such as weather resistance, which indicates that the high electromagnetic shielding ability is continuously maintained even in an environment such as high temperature and high humidity. The material stability of itself has been significantly improved,
In addition, the bonding property with the elastomer material substrate is enhanced more effectively by the interposition of the adhesion-promoting base film, and it is useful because it can be widely expected to be applied as an EMC countermeasure material with higher reliability. It is possible to provide an electromagnetic wave shield having high performance.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of an electromagnetic wave shield according to the present invention.

FIG. 2 is a sectional view showing another embodiment of the electromagnetic wave shield of the present invention.

[Description of Signs] 1: Electromagnetic wave shielding film 2: Substrate 3: Adhesion promoting base film 4: Protective film

Continued on the front page F-term (reference) 4F100 AA17E AA20E AA21E AA25E AA33E AB01E AB10E AB11E AB12B AB12C AB12E AB13B AB13C AB13E AB17B AB17C AB20B AB20C AB20E AB24B AB24C AB25B AB25C AB31 BA01B BA00 BAC GB41 JB02D JD08B JD08C JG01A JK09D JK13 JL11E 5E321 AA23 BB23 BB25 BB44 BB53 BB57 GG05

Claims (10)

[Claims] 1. A substrate made of a conductive elastomer material, comprising Ag as a main component, Pd, and at least one or more of Cu, Au, Ti, Cr, Ta, and Mo. An electromagnetic wave shielding body characterized in that an electromagnetic wave shielding film formed of an Ag alloy material to which is added is laminated. 2. The electromagnetic wave shielding film according to claim 1, wherein Pd is added in a range of 0.1 to 3.0 wt%, and Cu and A are further added.
An electromagnetic wave shield formed of an Ag alloy material obtained by adding at least one or more elements of u, Ti, Cr, Ta, and Mo in a range of 0.1 to 3.0 wt%. body. 3. The electromagnetic wave shielding film according to claim 1 or 2,
An electromagnetic wave shield comprising a single film or a multilayer film of two or more films. 4. Ag according to any one of claims 1 to 3, wherein
An electromagnetic wave shield, wherein the alloy material is an evaporation material, and an electromagnetic wave shielding film is formed on the surface of the substrate by an evaporation method. 5. Ag according to any one of claims 1 to 3, wherein
An electromagnetic wave shielding body, wherein the alloy material is a sputtering target material, and an electromagnetic wave shielding film is formed on the surface of the substrate by a sputtering method. 6. An electromagnetic wave shield comprising a protective film made of a material having excellent corrosion resistance and weather resistance formed on the electromagnetic wave shield film according to any one of claims 1 to 5. 7. An electromagnetic wave shield comprising a protective film made of a material having excellent wear resistance, formed on the electromagnetic wave shield film according to claim 1. 8. An electromagnetic wave shield comprising a substrate and an electromagnetic wave shielding film according to any one of claims 1 to 7, wherein an adhesion promoting base film for promoting adhesion is formed. 9. The adhesion promoting underlayer film according to claim 8, wherein
O, IrO ₂ , ZnO ₂ , SiO ₂ , TiO ₂ , Ta ₂ O ₅ ,
An electromagnetic wave shield comprising at least one kind selected from ZrO ₂ or two or more kinds of materials containing these as main components. 10. The adhesion-promoting underlayer film according to claim 8, wherein
An electromagnetic wave shield comprising at least one selected from the group consisting of i, Ta, Ti, Mo, Cr, and Al, or two or more materials containing these as main components.