JP5410094B2 - Conductive film, method for producing the same, and high-frequency component - Google Patents

Description

  The present invention relates to a conductive film having a frequency dependency of a high-frequency transmission rate, a manufacturing method thereof, and a high-frequency component using the conductive film.

  As a high-frequency transmission line conventionally used in information processing equipment such as personal computers and wireless communication equipment such as mobile phones, a coaxial cable comprising an inner conductor 110, a dielectric 200 and an outer conductor 110 ′ as shown in FIG. Alternatively, as shown in FIG. 36, there is a metal waveguide 120 having a square cross section. Coaxial cables and waveguides have isotropic (same in both directions) transmission characteristics.

  Also, a high-frequency transmission line (FIG. 37) provided with a pair of strip-like conductors 130, 130 parallel to one surface of the dielectric substrate 210, ground conductors 140, 140 are provided on both surfaces of the dielectric substrate 210, and a conductor 130 is provided in the center. The high-frequency transmission line (FIG. 38), the ground conductor 130 is provided on one surface of the dielectric substrate 210, and the strip conductor 140 is provided on the other surface, and the strip-shaped conductor 130 is provided on one surface of the ceramic dielectric substrate 210. And a high-frequency transmission line (FIG. 40) having ground conductors 140 and 140 disposed on both sides thereof.

  Japanese Patent Application Laid-Open No. 7-336113 discloses a high-frequency transmission line having a conductor film having a film thickness of 1.14 to 2.75 times the skin depth at the operating frequency. A configuration example of this high-frequency transmission line is shown in FIGS. The conductor films 130 and 140 provided in parallel on the ceramic dielectric substrate 210 have no frequency dependency of the high-frequency transmission rate depending on the frequency. However, if the high frequency transmission rate is dependent on the frequency, various useful high frequency components can be obtained.

  Accordingly, an object of the present invention is to provide a conductive film having a frequency dependency of a high-frequency transmission rate, a manufacturing method thereof, and a high-frequency component using such a conductive film.

As a result of earnest research in view of the above object, the present inventor has formed a number of fine pores while applying pressure during energization after forming a two-layer metal thin film having different electrical resistances to be joined to a plastic film via a gradient composition layer. Alternatively, the inventors have found that a conductive film having a frequency dependency of a high-frequency transmission rate can be obtained by forming a concave portion, and have arrived at the present invention.

That is, the conductive film of the present invention has a plastic film, a first metal thin film provided on at least one surface thereof, and a second metal thin film formed thereon, and the first and second The metal thin film has different electric resistance, the thickness of the metal thin film with the smaller electric resistance is 0.1-1 μm, the thickness of the metal thin film with the larger electric resistance is 10-70 nm, Between the first metal thin film and the second metal thin film, a gradient composition layer is formed in which the metal composition ratio changes in the thickness direction, and in the gradient composition layer, the second metal thin film is formed . The composition ratio decreases from the second metal thin film to the first metal thin film, and has at least a number of fine holes or recesses opened on the second metal thin film side. Alternatively, the recess is formed while pressing the second metal thin film during energization. It is characterized in.

In this conductive film, a gradient composition layer in which the proportion of the first metal decreases from the first metal thin film to the plastic film 10 is also formed between the plastic film and the first metal thin film. It is preferable.

  In a preferred example of the conductive film, the first metal is nickel and the second metal is copper. In this case, the thickness ratio between the first metal thin film and the second metal thin film is preferably 1/20 to 1/2. Specifically, the thickness of the first metal thin film is preferably 10 to 70 nm, and the thickness of the second metal thin film is preferably 0.1 to 1 μm.

  In another preferred example of the conductive film, the first metal is copper and the second metal is nickel. In this case, the thickness ratio of the first metal thin film to the second metal thin film is preferably 2/1 to 20/1. Specifically, the thickness of the first metal thin film is preferably 0.1 to 1 μm, and the thickness of the second metal thin film is preferably 10 to 70 nm.

  In still another preferred example of the conductive film, the second metal thin film is a deposited layer.

  In still another preferred example of the conductive film, the second metal thin film is composed of the second metal deposition layer and the second metal plating layer.

  In still another preferred example of the conductive film, the first metal thin film is a deposited layer.

The fine holes or recesses preferably have an average opening diameter of 0.1 to 100 μm. The average density of the fine holes or recesses is preferably 500 / cm ² or more.

  In the method for producing a conductive film of the present invention, a first metal thin film and a second metal thin film are sequentially formed on at least one surface of a plastic film, and the obtained composite film is bonded to the surface with a large number of hard particles. By passing between one roll and a second roll having a smooth surface, a plurality of fine holes or recesses that are opened at least on the thin film side of the second metal are formed. The thin film is energized.

The pressing force of the roll is preferably 70 kgf / mm width or more. The voltage and current density applied to the second metal thin film are preferably 5 V or more and 20 A / m ² or more, respectively.

  The high frequency component of the present invention includes the conductive film.

  Preferred examples of the high-frequency component include a high-frequency transmission line in which two conductive films are arranged in parallel, and a high-frequency filter having the high-frequency transmission line.

  Since the conductive film of the present invention has frequency dependency of the high-frequency transmission rate, it is useful for various high-frequency components. For example, when used in a high-frequency transmission line, it is possible to efficiently transmit a desired frequency band and cut other frequency bands.

It is sectional drawing which shows the electrically conductive film by one Example of this invention. FIG. 2 is an enlarged cross-sectional view schematically showing a portion A in FIG. FIG. 2 is an enlarged cross-sectional view schematically showing an A ′ portion of FIG. 1 (b). FIG. 2 is an enlarged cross-sectional view schematically showing a portion A ″ in FIG. 1 (b). It is sectional drawing which shows the conductive film by another Example of this invention. FIG. 3 is an enlarged cross-sectional view schematically showing a B part in FIG. 2 (a). It is sectional drawing which shows the electrically conductive film by another Example of this invention. FIG. 4 is an enlarged cross-sectional view schematically showing a C portion in FIG. 3 (a). It is sectional drawing which shows the electrically conductive film by another Example of this invention. FIG. 5 is an enlarged cross-sectional view schematically showing a D part in FIG. 4 (a). It is a perspective view which shows the electrically conductive film by another Example of this invention. It is a perspective view which shows the electrically conductive film by another Example of this invention. It is a perspective view which shows the electrically conductive film by another Example of this invention. It is the schematic which shows an example of the apparatus which supplies with electricity, forming a micropore in a composite film. FIG. 9 is a partially enlarged perspective view of the apparatus of FIG. FIG. 9 is a partial enlarged cross-sectional view showing a state where electricity is supplied while forming fine holes in a composite film having a metal thin film on one surface in the apparatus of FIG. FIG. 9 is a partially enlarged cross-sectional view showing a state where power is supplied while forming fine holes in a composite film having metal thin films on both sides in the apparatus of FIG. 1 is a perspective view showing a high frequency transmission line according to an embodiment of the present invention. It is a perspective view which shows the high frequency filter by one Example of this invention. It is the schematic which shows the state which connected the oscillator and the receiver to the high frequency transmission line. It is a circuit diagram which shows roughly the structure of the oscillator used for the measurement of a high frequency transmission rate. It is the schematic which shows the signal pattern at the time of transmitting so that a signal may be output from the (+) side from an oscillator. It is the schematic which shows the signal pattern at the time of transmitting so that a signal may be output from the (-) side from an oscillator. 3 is a graph showing the relationship between the frequency and the high-frequency transmission rate in the high-frequency transmission line of Example 1. 6 is a graph showing the relationship between the frequency and the high-frequency transmission rate in the high-frequency transmission line of Example 2. 6 is a graph showing the relationship between the frequency and the high-frequency transmission rate in the high-frequency transmission line of Example 3. 6 is a graph showing the relationship between the frequency and the high-frequency transmission rate in the high-frequency transmission line of Example 4. 6 is a graph showing the relationship between the frequency and the high-frequency transmission rate in the high-frequency transmission line of Example 5. FIG. 22 is an enlarged view of FIG. 10 is a graph showing the relationship between the frequency and the high-frequency transmission rate in the high-frequency transmission line of Example 6. FIG. 24 is an enlarged view of FIG. 10 is a graph showing the relationship between the frequency and the high-frequency transmission rate in the high-frequency transmission line of Example 7. 10 is a graph showing the relationship between the frequency and the high-frequency transmission rate in the high-frequency transmission line of Example 8. 10 is a graph showing the relationship between the frequency and the high-frequency transmission rate in the high-frequency transmission line of Example 9. FIG. 28 is an enlarged view of FIG. 27. 6 is a graph showing the relationship between the frequency and the high-frequency transmission rate in the high-frequency transmission line of Comparative Example 1. 6 is a graph showing the relationship between the frequency and the high-frequency transmission rate in the high-frequency transmission line of Comparative Example 2. 10 is a graph showing the relationship between the frequency and the high-frequency transmission rate in the high-frequency transmission line of Comparative Example 3. 6 is a graph showing the relationship between the frequency and the high-frequency transmission rate in the high-frequency transmission line of Comparative Example 4. 10 is a graph showing the relationship between the frequency and the high-frequency transmission rate in the high-frequency transmission line of Comparative Example 5. 14 is a graph showing the relationship between the frequency and the high-frequency transmission rate in the high-frequency transmission line of Comparative Example 6. It is a perspective view which shows the example of the conventional high frequency transmission line. It is a perspective view which shows another example of the conventional high frequency transmission line. It is a perspective view which shows another example of the conventional high frequency transmission line. It is a perspective view which shows another example of the conventional high frequency transmission line. It is a perspective view which shows another example of the conventional high frequency transmission line. It is a perspective view which shows another example of the conventional high frequency transmission line.

[1] Conductive film
(1) Structure FIGS. 1 (a) to (d) show an example of the conductive film of the present invention. The first and second metal thin films 11a and 11b are uniformly formed on one surface of the plastic film 10, and the composition ratio between the first metal and the second metal is between the metal thin films 11a and 11b. A gradient composition layer 12 that changes in the thickness direction is formed, and a plurality of fine holes 14 are formed in both metal thin films 11a and 11b while being pressed during energization.

  In the gradient composition layer 12, the metal composition ratio is preferably changed substantially continuously. It is preferable that a gradient composition layer 12 ′ in which the metal ratio decreases from the metal thin film 11 a to the plastic film 10 is provided between the plastic film 10 and the metal thin film 11 a. FIG. 1 (c) schematically shows a state in which the second metal atom 11b ′ partially enters between the first metal atoms 11a ′, and FIG. 1 (d) shows the first metal atom 11a 1 schematically shows a state where 'partially enters between the plastic molecules 10' of the film 10.

  The large number of fine holes 14 are formed by a roll having fine particles with high hardness on the surface as will be described later, and thus have various depths, but need not penetrate through the plastic film 10.

  FIG. 2 (a) and FIG. 2 (b) show another example of the conductive film. In this conductive film, since the first metal thin film 11a is made of a metal foil, an adhesive layer 13 is provided between the first metal thin film 11a and the plastic film 10. This conductive film is the same as that shown in FIG.

  FIG. 3 (a) and FIG. 3 (b) show still another example of the conductive film. In this conductive film, the first and second metal thin films 11a and 11b are uniformly formed on both surfaces of the plastic film 10, and a plurality of fine holes 14 are provided in the first and second metal thin films 11a and 11b. Except for this, it is the same as that shown in FIG.

  FIG. 4 shows still another example of the conductive film. First and second metal thin films 11a and 11b are formed on both surfaces of the plastic film 10, and a large number of fine holes 14 substantially penetrate the conductive film. The metal thin films 11a and 11b are considered to be plastically deformed during the formation of the through holes.

  FIG. 5 shows still another example of the conductive film. This conductive film is the same as that shown in FIG. 1, except that two strip-shaped laminated metal thin films made of the first and second metal thin films 11a and 11b are formed on one surface of the plastic film 10. is there.

  FIG. 6 shows still another example of the conductive film. In this conductive film, one belt-like laminated metal thin film (consisting of first and second metal thin films 11a and 11b) is formed on one surface of the plastic film 10, and the laminated metal thin films (first and second thin films 11a and 11b) are formed on the other surface. 1 is the same as that shown in FIG. 1 except that the second metal thin films 11a and 11b are uniformly formed.

  FIG. 7 shows still another example of the conductive film. This conductive film is the same as that shown in FIG. 1 except that three belt-like laminated metal thin films (each comprising first and second metal thin films 11a and 11b) are provided on one surface of the plastic film 10. It is.

(2) Plastic film The resin constituting the plastic film 10 is not particularly limited. For example, polyester, polyphenylene sulfide, polyamide, polyimide, polyamideimide, polyethersulfone, polyetheretherketone, polycarbonate, acrylic resin, polystyrene, ABS resin , Polyurethane, fluororesin, polyolefin (polyethylene, polypropylene, etc.), polyvinyl chloride, thermoplastic elastomer and the like. Among them, high heat resistant resins such as polyester, polyphenylene sulfide, polyamide, polyimide, polyamideimide, polyethersulfone and polyetheretherketone are preferable, and polyester, polyphenylene sulfide and polyimide are particularly preferable. Examples of the polyester include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate, and polybutylene naphthalate. Of these, PET films and PBT films are preferred because they are commercially available at low cost.

(3) Metal thin film It is preferable that the first and second metal thin films 11a and 11b have different electric resistances. The difference in electrical resistance between the first and second metal thin films 11a and 11b is preferably 2 × 10 ⁻⁶ Ω · cm or more at room temperature, and more preferably 4 × 10 ⁻⁶ Ω · cm or more. .

As the first and second metals, copper [resistivity (20 ° C.): 1.6730 × 10 ⁻⁶ Ω · cm], aluminum [resistivity (20 ° C.): 2.6548 × 10 ⁻⁶ Ω · cm], silver [resistance Rate (20 ° C): 1.59 × 10 ^-6 Ω · cm], Gold [Resistivity (20 ° C): 2.35 × 10 ^-6 Ω · cm], Platinum [Resistivity (20 ° C): 10.6 × 10 ^-6 Ω・ Cm], nickel [resistivity (20 ° C): 6.84 × 10 ^-6 Ω · cm], cobalt [resistivity (20 ° C): 6.24 × 10 ^-6 Ω · cm], palladium [resistivity (20 ° C) : 10.8 × 10 ⁻⁶ Ω · cm], tin [resistivity (0 ° C.): 11.0 × 10 ⁻⁶ Ω · cm], and alloys thereof.

  The first and second metals are selected from the above so as to have different electric resistances. Preferred combinations of the first metal / second metal are copper / nickel and nickel / copper.

  Regardless of the electric resistance of the first metal and the second metal, the thickness ratio of the metal thin film having the smaller electric resistance and the metal thin film having the larger electric resistance is 2/1 to 20 / 1 is preferable. In particular, when both metal thin films are vapor-deposited films, this ratio is preferably 3/1 to 15/1. Specifically, the thickness of the metal thin film having the smaller electric resistance is preferably 0.1 to 35 μm, more preferably 0.1 to 1 μm, and most preferably 0.2 to 0.7 μm. Further, the thickness of the metal thin film having the larger electric resistance is preferably 10 nm to 20 μm, more preferably 10 to 70 nm, and most preferably 20 to 60 nm. If the thickness of the metal thin film having the smaller electrical resistance is less than 0.1 μm, the high-frequency transmission efficiency is poor. On the other hand, if it exceeds 1 μm, the frequency dependency of the high-frequency transmission rate is reduced.

  The first metal thin film 11a is preferably formed by vapor deposition or foil. The second metal thin film 11b is formed by vapor deposition of at least a layer bonded to the first metal thin film 11a. Therefore, the second metal thin film 11b may be a deposited film or a deposited film + plated layer.

(4) Gradient composition layer
(a) Between the first metal thin film and the second metal thin film, as shown in FIG. 1 (c), in the graded composition layer 12, the second metal atom 11b ′ is the same as the first metal atom 11a ′. Since it has partially penetrated, the composition ratio (concentration) of the second metal atom 11b ′ decreases from the second metal thin film 11b to the first metal thin film 11a. The gradient composition layer 12 in which the concentrations of both metal atoms 11a ′ and 11b ′ gradually change is estimated to be amorphous.

(b) Between the metal thin film and the plastic film As shown in FIG. 1 (d), in the gradient composition layer 12 ′, the first metal atoms 11a ′ partially enter between the plastic molecules 10 ′ of the film 10. Therefore, the composition ratio (concentration) of the first metal atom 11a ′ decreases from the first metal thin film 11a to the plastic film 10.

(5) Micropores or recesses In order to obtain excellent high-frequency transmission characteristics, micropores or recesses (sometimes collectively referred to as “micropores”) 14 are formed in the conductive film 1. As shown in FIG. 1, the fine hole 14 may be partway through the plastic film 10 as long as it penetrates at least the metal thin films 11a and 11b. Of course, as shown in FIG. 4, the fine holes 14 may penetrate the plastic film 10.

  The average opening diameter of the micropores 14 is preferably 0.1 to 100 μm, and more preferably 0.5 to 50 μm. It is technically difficult to make the average opening diameter of the fine holes 14 less than 0.1 μm. On the other hand, when the average opening diameter of the micropores 14 exceeds 100 μm, the strength of the conductive film 1 decreases. In order to have good transmission loss, the upper limit of the average aperture diameter is particularly preferably 20 μm, and most preferably 10 μm. The average opening diameter is obtained by measuring and averaging the opening diameters of the plurality of fine holes 14 in an arbitrary field of view of the atomic force micrograph of the conductive film 1.

The average density of the fine holes 14 is preferably 500 / cm ² or more, and more preferably 5 × 10 ³ / cm ² or more. If the average density of the fine holes 14 is less than 500 / cm ² , the transmission loss is too large. In order to suppress the transmission loss, the average density of the micropores 14 is preferably in the range of 1 × 10 ⁴ ~3 × 10 ⁵ cells / cm ^2, a 1 × 10 ⁴ ~2 × 10 ⁵ cells / cm ² Is more preferable. The average density of the micropores 14 is also determined by measuring the number of micropores 14 in an arbitrary field of view of the atomic force micrograph of the conductive film 1 and averaging it per unit area.

  As shown in FIG. 4 (b), the metal thin films 11 a and 11 b are plastically deformed by the formation of the fine holes 14, and some of them extend along the wall surface of the fine holes 14. Due to plastic deformation of the metal thin films 11a and 11b, the frequency dependence of the high-frequency transmission rate is improved. This is considered to be because both metals are mixed in the gradient composition layer 12 due to plastic deformation of the metal thin films 11a and 11b.

(6) Resistivity In order to obtain high frequency dependency of the high frequency transmission rate, the resistivity of the laminate composed of the metal thin films 11a and 11b (simply referred to as “the resistivity of the conductive film”) is the combination of copper and nickel. 2 × 10 ^{−6 to} 150 × 10 ⁻⁶ Ω · cm is preferable, and 3 × 10 ^{−6 to} 100 × 10 ⁻⁶ Ω · cm is more preferable.

[2] Method for Producing Conductive Film Conductive film 1 is formed by forming first metal thin film 11a on one surface or both surfaces of plastic film 10 by vapor deposition or foil bonding, and then depositing it on the film by vapor deposition, vapor deposition or plating. The second metal thin film 11b is formed, and the resulting composite film is passed between a first roll having a large number of hard particles attached to the surface and a second roll having a smooth surface, thereby at least a second metal. A large number of fine holes 14 are formed on the thin film 11b side, and the second metal thin film 11b is energized at that time. Since the gradient composition layer 12 is formed between the first metal thin film 11a and the second metal thin film 11b, the gradient composition layer 12 ′ is formed between the plastic film 10 and the first metal thin film 11a. There is no need. For example, in the conductive film 1 shown in FIG. 2, the first metal thin film 11a made of a metal foil is bonded to the plastic film 10, and the second metal thin film 11b is formed by a vapor deposition method or a vapor deposition method and a plating method. Energize while forming 14.

(1) Formation of metal thin film Metal vapor deposition is performed by, for example, physical vapor deposition such as vacuum vapor deposition, sputtering, or ion plating, chemical vapor deposition such as plasma CVD, thermal CVD, or photo CVD. It can be carried out. When the 2nd metal thin film 11b consists of a vapor deposition layer and a plating layer, a plating layer can be formed by a well-known method.

(2) Formation of micropores FIG. 8 shows an apparatus for forming micropores 14 while energizing a composite film 1 ′ in which first and second metal thin films 11a and 11b are formed in a plastic film 10. The composite film 1 ′ unwound from the unwinder 55 is passed through a dancer roll 60 and an expander roll 61, and between a first roll 64 having a large number of high-hardness fine particles on the surface and a second roll 65 having a smooth surface. In addition, a large number of fine holes 14 opened at least on the second metal thin film 11b side are formed by passing under a uniform pressing force, and at this time, electrode rolls 62a and 62b are formed with respect to the second metal thin film 11b. Energize by. The obtained conductive film 1 is wound around a winder 56 through a pair of Z wrap rolls 67 and 67 and a dancer roll 68.

  As shown in FIG. 9, the pair of electrode rolls 62a and 62b are provided before and after the first roll 64, and the pair of electrode rolls 63a and 63b are provided before and after the second roll 65. A power source 70a (70b) is connected to the boxes 620a and 620b (630a and 630b) that support the electrode rolls 62a and 62b (63a and 63b), and voltage is applied to the electrode rolls 62a and 62b (63a and 63b). Can do. ,

  The first roll 64 is obtained by attaching a large number of hard fine particles (diamond fine particles) to the surface of a metal roll by a nickel or chromium plating electrodeposition method (diamond roll). The second roll 65 is a hard metal roll. Details of the diamond roll are described in JP-A-2002-59487.

(a) When having a metal thin film on one surface FIG. 10 shows a state in which fine holes are formed in the composite film 1 ′ having the first and second metal thin films 11a and 11b while being energized. With the metal thin film facing the first roll 64, the second metal thin film is transferred by the electrode rolls 62a and 62b while the composite film 1 'is passed between the first and second rolls 64 and 65 under a uniform pressing force. Energize 11b.

The power source 70a may be either a DC power source or an AC power source. The DC voltage may be a pulse voltage. The voltage and current density are appropriately set according to the frequency of the high frequency signal. The voltage is preferably 5 V or more, and more preferably 8 V or more. If the voltage is less than 5 V, the increase in resistance is insufficient. The upper limit of the voltage is preferably 30 V, and more preferably 25 V. When an AC power source is used, the frequency is preferably 10 Hz to 1 MHz, and more preferably 100 to 10,000 Hz. The current density is preferably 20 A / m ² or more, and more preferably 25 A / m ² or more. The upper limit of the current density is preferably 70 A / m ^{2 and} more preferably 50 A / m ² .

  The pressing force applied to the composite film 1 ′ by the first and second rolls 64 and 65 may be appropriately set according to the frequency of the high frequency signal, but is preferably 70 kgf / mm width or more, and 80 to 1,000 kgf / mm. The width is more preferable.

  The conveying speed of the composite film 1 ′ is preferably 20 to 100 m / min, and more preferably 25 to 80 m / min. If this speed is less than 20 m / min, the plastic film 10 may be deteriorated. On the other hand, if it exceeds 100 m / min, the electrical resistance will not increase sufficiently.

  In addition, when passing composite film 1 'between the 1st and 2nd rolls 64 and 65 as needed, you may make a metal thin film the 2nd roll 65 side.

(b) Case of having metal thin films on both surfaces FIG. 11 shows a state in which fine holes are formed in the composite film 1 ′ having the first and second metal thin films 11a and 11b on both surfaces while being energized. In this case, the metal thin film 11b is energized by the pair of electrode rolls 62a and 62b, and the metal thin film 11b is energized by the pair of electrode rolls 63a and 63b.

  By applying the pressure as described above, excellent frequency dependence of the high-frequency transmission rate can be obtained.

[3] High-frequency component The high-frequency component of the present invention includes the conductive film. Preferred examples of the high frequency component include a high frequency transmission line and a high frequency filter.

(1) High-frequency transmission line FIG. 12 shows an example of the high-frequency transmission line of the present invention. In this high-frequency transmission line, two strip-like conductive films 100, 100 are arranged in parallel on the upper surface of a dielectric substrate 2 made of plastic, insulating ceramics or the like. The strip-shaped conductive films 100 and 100 are obtained by slitting the conductive film 1 by a known method. Since the electric field concentrates between the two strip-shaped conductive films 100, 100, a high-frequency signal can be transmitted efficiently. In order to obtain an excellent high frequency transmission property, the dielectric substrate 2 preferably has a convex portion 20 between the two strip-like conductive films 100 and 100.

Width d ₁ of each conductive film 100, 100 is appropriately set according to the frequency and amplitude such as of a high-frequency signal is preferably in the range of 1 to 10 mm, and more preferably 1.5 to 7 mm. If the width d ₁ is 1mm or more, with sufficient frequency signal transmission property. Further, even if the width d ₁ is greater than 10 mm, further improvement in high-frequency signal transmission is not obtained.

The distance d2 between the _two strip-like conductive films 100, 100 is preferably 1 to 10 mm, and more preferably 1.5 to 7 mm. Distance d ₂ is that it is less than 1mm is insufficient high frequency signal transmission property, whereas the radiation loss is large but 10 mm greater. The height h of the convex portion 20 is preferably 1 to 10 mm, and more preferably 1.5 to 7 mm.

  The conductive films 100 and 100 are not limited to being disposed on the same surface of the dielectric substrate, but are on the opposite inner surface of the U-shaped dielectric substrate or the orthogonal inner surface of the L-shaped dielectric substrate. It may be arranged above.

  The high-frequency transmission line of the present invention has excellent frequency dependence and high-frequency transmission rate, and does not change with time in high-frequency characteristics. In addition, since it has a relatively high electrical resistance, the termination resistor may be omitted in some cases. The conductive film of the present invention has an excellent filter function because it has a frequency band with a high-frequency transmission rate of 100% or more and a frequency band with a high-frequency transmission rate of almost 0%. Further, since there is anisotropy in the transmission direction, it also has a hacker prevention function that prevents the entry of signals from the outside.

(2) High-frequency filter The high-frequency filter of the present invention has a simple structure in which an input terminal and an output terminal are connected to the high-frequency transmission line. FIG. 13 shows an example of such a high frequency filter. When the second metal thin film 11b has an electric resistance smaller than that of the first metal thin film 11a, it is preferable to provide the terminal 4 on the second metal thin film 11b. The high frequency filter of the present invention has excellent frequency dependence and high frequency transmission rate.

(3) Other high-frequency components Other high-frequency components include high-frequency resonators, high-frequency electrodes, high-frequency signal distributors, planar transmission line-waveguide line converters, high-frequency amplification elements, antennas (for example, antennas for electronic tags), etc. Also mentioned. These high frequency components may also have a simple structure in which an input terminal and an output terminal are connected to the high frequency transmission line.

  The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1
(1) Production of strip-shaped conductive film
(i) Preparation of composite film Biaxially stretched PET film [thickness: 12 μm, dielectric constant: 3.2 (1 MHz), dielectric loss tangent: 1.0% (1 MHz), melting point: 265 ° C, glass transition temperature: 75 ° C] A copper layer having a thickness of 0.3 μm was formed on one surface by a vacuum evaporation method, and a nickel layer having a thickness of 20 nm was formed thereon by a vacuum evaporation method. As a result of measuring the electrical resistance in the length direction of the test piece obtained by cutting the obtained composite film into 50 cm × 3 mm, it was 8Ω.

(ii) Pressurization energization Using the apparatus shown in FIG. 8, between the first roll (diamond fine particle size 3 μm) 64 and the second roll 65, under a pressure of 100 kgf / mm width, 30 m / min. While passing through the composite film at a speed, the nickel layer was brought into contact with the pair of electrode rolls 62a and 62b, and a pulse voltage of 24 V (30 milliseconds for both on and off) was applied from the power source 70a. The current density was 35 A / m ^2. The average density of micropores in the obtained conductive film was 5 × 10 ⁴ holes / cm ² . The electrical resistance (measured in the length direction) of the test piece obtained by cutting the conductive film into 50 cm × 3 mm was 100Ω.

(2) Production of a high-frequency transmission line Two strip-shaped conductive films were bonded in parallel to a vinyl chloride resin substrate so that the PET film was on the substrate side, and a parallel-line type high-frequency transmission line shown in FIG. 12 was produced. (Length: 50 cm, distance d ₂ between the _two strip-like conductive films: 3 mm).

Example 2
A strip-shaped conductive film was produced in the same manner as in Example 1 except that a pulse voltage of 15 V (current density of 35 A / m ² ) was applied. The electric resistance of the strip-shaped conductive film was 32Ω, and the average density of micropores was 5 × 10 ⁴ pieces / cm ² . A high frequency transmission line was produced in the same manner as in Example 1 except that this strip-like conductive film was used.

Example 3
A strip-shaped conductive film was produced in the same manner as in Example 1 except that a pulse voltage of 18 V (current density of 35 A / m ² ) was applied. The electric resistance of the strip-shaped conductive film was 49Ω, and the average density of micropores was 5 × 10 ⁴ pieces / cm ² . A high frequency transmission line was produced in the same manner as in Example 1 except that this strip-like conductive film was used.

Example 4
A strip-shaped conductive film was produced in the same manner as in Example 1 except that a pulse voltage of 18 V (current density of 35 A / m ² ) was applied to the composite film at a speed of 60 m / min. The electric resistance of the strip-shaped conductive film was 18Ω, and the average density of micropores was 5 × 10 ⁴ pieces / cm ² . A high frequency transmission line was produced in the same manner as in Example 1 except that this strip-like conductive film was used.

Example 5
A strip-shaped conductive film was produced in the same manner as in Example 1 except that an AC voltage of 10 V (current density of 45 A / m ² ) was applied at a frequency of 5,000 Hz and then cut at a width of 5 mm. The electric resistance of the strip-shaped conductive film was 52Ω, and the average density of micropores was 5 × 10 ⁴ pieces / cm ² . A high frequency transmission line was produced in the same manner as in Example 1 except that this strip-like conductive film was used.

Example 6
A strip-shaped conductive film was produced in the same manner as in Example 1 except that an alternating voltage of 10 V (current density of 30 A / m ² ) was applied at a frequency of 5,000 Hz, and then cut at a width of 5 mm. The electric resistance of the strip-shaped conductive film was 47 Ω, and the average density of micropores was 5 × 10 ⁴ pieces / cm ² . A high frequency transmission line was produced in the same manner as in Example 1 except that this strip-like conductive film was used.

Example 7
A copper layer having a thickness of 0.3 μm was formed on one surface of the PET film by a vacuum deposition method, and then a nickel layer having a thickness of 50 nm was formed. The electrical resistance (measured in the longitudinal direction) of a test piece obtained by cutting the obtained composite film into 50 cm × 5 mm was 8Ω. The composite film was passed through the roll pairs 64 and 65 at a speed of 30 m / min under a pressure of 500 kgf / mm width, and a pulse voltage of 10 V (current density was 30 A / m ² ) was applied. A strip-shaped conductive film was produced in the same manner as in Example 1 except that the film was cut in step 1. The electric resistance of the strip-shaped conductive film was 16Ω, and the average density of micropores was 5 × 10 ⁴ pieces / cm ² . A high frequency transmission line was produced in the same manner as in Example 1 except that this strip-like conductive film was used.

Example 8
A composite film was produced in the same manner as in Example 7 except that a biaxially stretched PET film having a thickness of 16 μm was used and the thickness of the copper layer was changed to 0.5 μm. The electrical resistance of the test piece obtained by cutting the composite film into 50 cm × 5 mm was 8Ω. The electric resistance of the strip-shaped conductive film obtained by forming and cutting micropores in the composite film in the same manner as in Example 7 was 17Ω, and the average density of micropores was 5 × 10 ⁴ holes / cm ^2. It was. A high frequency transmission line was produced in the same manner as in Example 1 except that this strip-like conductive film was used.

Example 9
Biaxially stretched polyphenylene sulfide film (thickness: 12μm, dielectric constant: 3 (1 MHz), dielectric loss tangent: 0.002 (1 MHz), melting point: 285 ° C, glass transition temperature: 90 ° C) by vacuum evaporation After forming a nickel layer having a thickness of 50 nm, a copper layer having a thickness of 0.2 μm was formed. The test piece obtained by cutting the obtained composite film into 50 cm × 3 mm had an electric resistance of 10Ω. The electric resistance of the strip-shaped conductive film obtained by forming and cutting micropores in the composite film in the same manner as in Example 7 was 16Ω, and the average density of micropores was 5 × 10 ⁴ holes / cm ^2. It was. A high frequency transmission line was produced in the same manner as in Example 1 except that this strip-like conductive film was used.

Comparative Example 1
Biaxially stretched polyimide film (thickness: 25 μm, dielectric constant: 3.3 (1 MHz), dielectric loss tangent: 0.0079 (1 MHz), glass transition temperature: 280 ° C or higher) is bonded to 12 μm thick rolled copper foil. did. A strip-shaped conductive film was produced in the same manner as in Example 1 except that a pulse voltage of 18 V (current density of 35 A / m ² ) was applied to the obtained laminated film. There was no change in electrical resistance before and after applying pressure. A high frequency transmission line was produced in the same manner as in Example 1 except that this strip-like conductive film was used.

Comparative Example 2
A strip-shaped conductive film was produced in the same manner as in Comparative Example 1 except that a pulse voltage of 20 V (current density of 40 A / m ² ) was applied. There was no change in electrical resistance before and after applying pressure. A high frequency transmission line was produced in the same manner as in Example 1 except that this strip-like conductive film was used.

Comparative Example 3
A strip-shaped conductive film was produced in the same manner as in Comparative Example 1 except that a pulse voltage of 25 V (current density of 50 A / m ² ) was applied. There was no change in electrical resistance before and after applying pressure. A high frequency transmission line was produced in the same manner as in Example 1 except that this conductive film was used.

Comparative Example 4
A copper layer having a thickness of 3.0 μm was formed on one surface of the polyimide film by a vacuum deposition method, and a nickel layer having a thickness of 10 μm was formed thereon. In the same manner as in Example 7 for the obtained composite film, micropores were formed and the strip-like conductive film obtained by cutting had an electric resistance of 0.1Ω, and the average density of micropores was 5 × 10 ⁴ / cm ² . A high frequency transmission line was produced in the same manner as in Example 1 except that this strip-like conductive film was used.

Comparative Example 5
A strip-shaped conductive film was produced in the same manner as in Example 7 except that the fine holes were not formed. The electric resistance of the strip-shaped conductive film was 8Ω. A high frequency transmission line was produced in the same manner as in Example 1 except that this strip-like conductive film was used.

Comparative Example 6
A strip-shaped conductive film was produced in the same manner as in Example 7 except that fine holes were formed while passing through the roll pairs 64 and 65 at a speed of 30 m / min under a pressure of 500 kgf / mm width without energization. The electric resistance of the strip-shaped conductive film was 13Ω, and the average density of micropores was 5 × 10 ⁴ pieces / cm ² . A high frequency transmission line was produced in the same manner as in Example 1 except that this strip-like conductive film was used.

  Table 1 shows the production conditions and physical properties of the strip-like conductive films of Examples 1 to 9 and Comparative Examples 1 to 6.

Table 1 (continued)

Table 1 (continued)

Table 1 (continued)

Notes: (1) Resistivity of laminated metal consisting of first and second metal thin films. The length of the laminated metal was 50 cm, and the width was 3 mm (Examples 1 to 4) and 5 mm (Examples 5 to 9, Comparative Examples 5 and 6).
(2) Resistivity of laminated metal composed of first and second metal thin films and a gradient composition layer therebetween. The length of the laminated metal was 50 cm, and the width was 3 mm (Examples 1 to 4) and 5 mm (Examples 5 to 9 and Comparative Examples 4 to 6).
(3) Apply pulse voltage (30 milliseconds for both on / off).
(4) No energization when forming fine holes.

  The high frequency transmission rates of the high frequency transmission lines obtained in Examples 1 to 9 and Comparative Examples 1 to 6 were measured by the following method.

(a) Measuring spurious characteristics of high-frequency oscillators
(i) Production of high-frequency transmission line for measuring spurious characteristics A copper layer having a thickness of 0.3 μm was formed on one surface of a biaxially stretched PET film by a vacuum deposition method, and slit to a width of 5 mm. Two strips of copper / PET film with a length of 50 cm were bonded in parallel to the vinyl chloride resin substrate with a distance of d ₂ of 3 mm with the PET film facing down. A high-frequency transmission line for measuring spurious characteristics was fabricated.

(ii) Spurious characteristic measurement As shown in FIG. 14, a high-frequency oscillator 5 is connected to one end of a laminated film 1 '', 1 '' of a high-frequency transmission line for measuring spurious characteristics via a cable 70 and a hook clip 7. A high frequency receiver 6 was connected to the other end. In order to match the impedance and accurately measure the high-frequency transmission rate, the matching unit 8 is provided immediately after the high-frequency oscillator 5 and immediately before the receiver 6. As shown in FIG. 15, a high-frequency oscillator 5 includes a voltage-controlled oscillator (VCO) 51, three high-frequency oscillation modules 52, 52 ′, 52 ″ and 2 that are switched according to the frequency of a signal to be transmitted. A plurality of high-frequency amplifiers 53 and 53 ′ are provided. The high frequency oscillator 5 can transmit signals in the ranges of 100 to 200 MHz, 260 to 550 MHz, and 600 to 1,050 MHz. Signals of 100, 200, 300, 500, 700 and 1,000 MHz were transmitted from the oscillator 5, and the spurious characteristics were examined. The results are shown in Table 2. This high-frequency oscillator 5 generated less harmonics and had no spurious other than harmonics.

(b) Transmission coefficient setting Connect oscillator 5 and receiver 6 with cable 70 (see Fig. 14), and increase the frequency from 120 MHz to 1,050 MHz at intervals of 2 to 6 MHz with an output amplitude of 1.0 V. The signal was transmitted from 5. As shown in FIG. 16 (a), when the signal is transmitted from the output terminals 50, 50 of the oscillator 5 so as to output from the (+) side (signal pattern 1), as shown in FIG. 16 (b), Input amplitude when both signals are transmitted from the output terminals 50 and 50 of the oscillator 5 so that the signal is output from the (-) side (signal pattern 2: phase shifted by 1/2 wavelength with respect to signal pattern 1) Asked. According to the formula: transmission coefficient = input amplitude (V) / output amplitude (V), the transmission coefficient at each frequency was obtained, and a frequency-transmission coefficient curve was created for each of signal patterns 1 and 2.

(c) Measurement of the high-frequency transmission rate The oscillator 5 and the receiver 6 are connected to the high-frequency transmission lines manufactured in Examples 1 to 9 and Comparative Examples 1 to 6 in the same manner as described above, and the matching unit 8 is immediately after the oscillator 5. And provided immediately before the receiver 6 (see FIG. 14). The signal (signal patterns 1 and 2) was transmitted from the oscillator 5 while increasing the frequency from 120 MHz to 1,050 MHz at intervals of 2 to 6 MHz with an output amplitude (V) of 1.0 V, and the input amplitude (V) was obtained. . Using the transmission coefficient obtained from the above-mentioned frequency-transmission coefficient curve, the high frequency transmission rate (%) at each measurement frequency is expressed by the formula: high frequency transmission rate (%) = input amplitude (V) / (output amplitude (V) × transmission coefficient. ) × 100. The results of plotting the relationship between the frequency and the high-frequency transmission rate are shown in FIGS.

  17 to 20, in the high-frequency transmission lines of Examples 1 to 4, the high-frequency transmission rate is approximately 100% or more in the bands of 320 to 350 MHz and 760 to 820 MHz with respect to the signal pattern 1, and is generally 600. It was 0% in a wide band of ~ 700 MHz and had frequency dependence. With respect to the signal pattern 2, the high-frequency transmission rate was approximately 100% or more in the bands of 140 to 180 MHz, 380 to 430 MHz, and 620 to 730 MHz, and the transmission characteristics were excellent. Due to the difference in signal pattern, the high frequency transmission rate band was different.

  From FIGS. 21 to 24, in the high-frequency transmission lines of Examples 5 and 6, the high-frequency transmission rate with respect to the signal pattern 1 is approximately 100% or more in a band of approximately 650 to 700 MHz, and is broad as approximately 400 to 500 MHz. It was 0% in the band. For signal pattern 2, the high-frequency transmission rate was approximately 100% or more in the band of approximately 320 to 360 MHz, and approximately 0% in the broad bands of approximately 600 to 700 MHz and 870 to 970 MHz. For signal patterns 1 and 2, the frequency dependence of the high-frequency transmission rate was present.

  From FIG. 25, in the high-frequency transmission line of Example 7, the high-frequency transmission rate with respect to the signal pattern 1 is approximately 100% or more in the bands of 140 to 220 MHz, 370 to 420 MHz, and 660 to 710 MHz. It was 0% in the band of ~ 800 MHz. In particular, 177 MHz showed a transmission rate of 770%. For signal pattern 2, the high-frequency transmission rate was approximately 100% or more in the bands of approximately 150 to 230 MHz, 330 to 350 MHz, and 730 to 820 MHz. For signal pattern 2, there was no band with a high-frequency transmission rate of 0%, and no band-removability was observed. Thus, it was found that a rectifying action was obtained due to the difference in signal pattern.

  From FIG. 26, the high-frequency transmission line of Example 8 has a high-frequency transmission rate of approximately 100% or more in the bands of 120 to 460 MHz, 750 to 840 MHz, and 900 to 1,010 MHz with respect to the signal pattern 1 and transmitted. It was excellent in nature. For signal pattern 2, the high-frequency transmission rate is approximately 100% or more in the bands of 190 to 310 MHz, 600 to 660 MHz, 770 to 800 MHz, and 970 to 1,010 MHz, and 0% in the band of 690 to 730 MHz. Met. Since no band-removability was observed for signal pattern 1, it was found that a rectifying action was obtained due to the difference in signal pattern.

  From FIGS. 27 and 28, in the high-frequency transmission line of Example 9, the high-frequency transmission rate with respect to the signal pattern 1 is generally 100% or more in the bands of 130 to 180 MHz, 370 to 410 MHz, and 970 to 1,010 MHz. 0% in the 430-530 MHz and 750-780 MHz bands. For signal pattern 2, the high-frequency transmission rate is approximately 100% or more in the bands of 130 to 180 MHz, 240 to 300 MHz, 320 to 360 MHz, and 780 to 860 MHz, and 0% in the band of 640 to 720 MHz. Met. In particular, the transmission rate was 2,715% at 344 MHz. Due to the difference in the signal pattern, the band where the high frequency is not transmitted and the band where the high frequency transmission rate is high are different.

  On the other hand, in the high-frequency transmission lines of Comparative Examples 1 to 3 (see FIGS. 29 to 31), since copper foil was used, a band and a high-frequency transmission rate where the high-frequency transmission rate was 100% or more compared to Examples 1 to 9 However, the 0% band was narrow and the frequency dependence of the high-frequency transmission rate was low.

  As is clear from FIG. 32, in the high-frequency transmission line of Comparative Example 4, the nickel layer of the conductive film is more than 70 nm and the copper layer is more than 1 μm, so the band where the high-frequency transmission rate is 0% does not appear. It was.

  As is clear from FIG. 33, the high frequency transmission line of Comparative Example 5 had a high frequency transmission rate of 0% in the band of 700 to 730 MHz with respect to the signal pattern 1. However, since the conductive film of this transmission line was not energized under pressure, the band where the high-frequency transmission rate was 0% was narrower than in Examples 1-9. In addition, the maximum value of the transmission rate was 580.1%, which was lower than Example 7 in which pressure was applied.

  As is clear from FIG. 34, in the high-frequency transmission line of Comparative Example 6, the high-frequency transmission rate is 0% in the band of 430 to 500 MHz and 750 to 770 MHz with respect to the signal pattern 1, and the signal pattern 2 In contrast, it was 0% in the bands of 610 to 650 MHz and 900 to 930 MHz. However, since this conductive film was not energized under pressure, the maximum value of the transmission rate was 578.4%, which was lower than Example 7 under energization under pressure.

Claims (12)

A plastic film, a first metal thin film provided on at least one surface of the plastic film, and a second metal thin film formed on the plastic film, wherein the first and second metal thin films have different electric resistances. The thickness of the metal thin film having the smaller electric resistance is 0.1 to 1 μm, the thickness of the metal thin film having the larger electric resistance is 10 to 70 nm, and the first metal thin film and the A gradient composition layer in which the metal composition ratio changes in the thickness direction is formed between the second metal thin film and the composition ratio of the second metal in the gradient composition layer is that of the second metal. The thin film decreases from the thin film to the first metal thin film, and has at least a plurality of fine holes or recesses opened on the second metal thin film side. A conductive film formed by applying pressure to a thin film during energization. 2. The conductive film according to claim 1, wherein the ratio of the first metal decreases from the first metal thin film to the plastic film 10 between the plastic film and the first metal thin film. An electrically conductive film having a gradient composition layer formed thereon. 3. The conductive film according to claim 1 or 2, wherein the first metal is nickel, the second metal is copper , and a thickness of the first metal thin film and the second metal thin film. A conductive film having a thickness ratio of 1/20 to 1/2 . 3. The conductive film according to claim 1 or 2, wherein the first metal is copper, the second metal is nickel , and the thickness of the first metal thin film and the second metal thin film. A conductive film having a thickness ratio of 2/1 to 20/1 . Conductive film in the conductive film according to any one of claims 1-4, wherein the fine holes or recesses, characterized in that it has a mean opening diameter of 0.1 to 100 [mu] m. 6. The conductive film according to claim 5 , wherein an average density of the fine holes or recesses is 500 / cm ² or more. In conductive film according to any one of claims 1 to 6 conductive film thin of the second metal is characterized by comprising a deposited layer, or deposited layer and the plating layer. In conductive film according to any one of claims 1 to 7 conductive film thin the first metal is characterized in that a vapor-deposited layer. A plastic film, a first metal thin film provided on at least one surface of the plastic film, and a second metal thin film formed on the plastic film, wherein the first and second metal thin films have different electric resistances. The thickness of the metal thin film having the smaller electric resistance is 0.1 to 1 μm, the thickness of the metal thin film having the larger electric resistance is 10 to 70 nm, and the first metal thin film and the A gradient composition layer in which the metal composition ratio changes in the thickness direction is formed between the second metal thin film and the composition ratio of the second metal in the gradient composition layer is that of the second metal. A method for producing a conductive film having a large number of fine holes or recesses which are reduced from a thin film to the first metal thin film and open at least on the second metal thin film side, (1) A thin film of the first metal on at least one surface of the plastic film; Serial to form a thin film of a second metal in sequence, by passing between the (2) a first roll and the surface obtained number of the hard particles the composite film was adheres to the smooth surface second roll, A method for producing a conductive film, comprising forming a large number of fine holes or recesses opened on at least the second metal thin film side, and energizing the second metal thin film. 10. The method for producing a conductive film according to claim 9 , wherein the pressing force of the roll is 70 kgf / mm width or more, and the voltage and current density applied to the second metal thin film are 5 V or more and 20 A / m ² or more. High-frequency component, characterized by comprising a conductive film according to any one of claims 1-8. 12. The high frequency component according to claim 11 , wherein the high frequency component is a high frequency transmission line in which the two conductive films are arranged in parallel.

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