KR102463385B1 - Metallized film and manufacturing method thereof - Google Patents

Abstract

A metallized film capable of forming a smooth thin copper film on a smooth fluororesin by using a physical vapor deposition method, and securing adhesion strength between the fluororesin and the copper film by appropriately selecting the type of physical vapor deposition, and providing a metallized film capable of forming wiring do. To provide a metallized film in which the thickness of the metal film by sputtering is controlled to a minimum, the electrolytic plating is possible by combining the vacuum deposition method, and the wiring can be formed with stable adhesion strength.

Description

Metallized film and manufacturing method thereof

[0001] The present invention relates to a metallized film suitably used for, for example, a wiring board having suitable signal wiring for transmitting a high-frequency digital signal, and a method for manufacturing the same.

In recent years, in order to realize high speed of the Internet, etc., portable communication devices have been required to process large-capacity signals. Therefore, in order to process such a large-capacity signal, a printed wiring board capable of responding to a high-speed signal is required. Since high-speed signals are high-frequency electrical signals, printed wiring boards used in these electronic devices are required to be able to suppress transmission loss when used in a high-frequency region. When the frequency of the electrical signal increases to 1 GHz or higher, the effect of the skin effect in which current flows only on the surface of the conductor becomes significant, and the transmission loss increases by changing the current transmission path due to the unevenness of the surface. Therefore, the wiring used for the printed wiring board for high frequency signal processing is desired to have a small surface roughness.

On the other hand, the base film which has a fluororesin as a main component as an insulating base material of the board|substrate for printed wiring boards is known. Since the fluororesin has a low dielectric constant and a low dielectric tangent, the transmission loss during high frequency signal transmission is small, and a base film containing a fluororesin as a main component is suitable as an insulating substrate for a printed wiring board for high frequency signal processing.

However, since a fluororesin lacks reactivity with another member, there exists a problem that the adhesive force (peel strength) between another member is low. Therefore, when the fluororesin is applied to the base film of the substrate for a printed wiring board, the adhesion between the base film and the copper foil (hereinafter, simply “adhesion ') is secured (Patent Document 1).

On the other hand, there is a method in which a thin metal layer is formed by sputtering on a smooth surface of a fluororesin film to ensure adhesion (Patent Document 2). In this case, the thickness of the formed metal film is as thin as 10 to 200 nm, and the metal film is formed by electrolytic copper plating on the thin metal film formed by sputtering to make it thick. At this time, the subtractive method and the semi-additive method are typical as a method of forming the wiring pattern of a printed wiring board. The subtractive method is a method of forming a circuit by removing unnecessary copper layer portions by thickening the metal film by electrolytic plating on the entire surface of the thin metal film. It is a method of forming the necessary circuit by etching copper foil with chemicals. At this time, a thin metal film as a power feeding part for electrolytic plating is required to have a copper film thickness of about 0.1 μm, and is formed by sputtering. On the other hand, the semi-additive method is a method of attaching a circuit pattern to an insulating layer substrate from the back. After forming a thin copper film on the entire surface of a resin substrate, a resist is formed in a portion where no pattern is formed, and electrolysis is performed in a portion without a resist. It is a method of forming a pattern by plating, removing the resist after plating, and performing soft etching on the entire surface to remove the thin copper film between the wirings. In the semi-additive method, a thin metal film as a power supply part for electrolytic plating is required to have a thickness of about 0.1 to 2.0 µm with a copper film thickness, and productivity is poor in film formation using only the sputtering method. Therefore, in some cases, after forming a thin metal film by sputtering, an electrolytic copper plating having a thickness of 1.5 µm to 2.0 µm is formed on the entire surface thereof, and wiring is formed by a semi-additive method using this thin copper film.

In any pattern formation, a short wiring length is required in a high-frequency region, and since it is arranged in a narrow area by reducing the size of a printed circuit board on which electronic components and the like are mounted, and improving the component mounting density, it has been required to form a fine-pitch circuit. In order to achieve this fine pitch, it is essential to suppress the etching non-uniformity in the wiring portion and suppress the thinning of the wiring in the etching. For the purpose of improving inter-wiring metal removability therefor, smoothing of the surface roughness is more demanded.

Japanese Patent Laid-Open No. 2004-6668 Japanese Patent No. 4646580 Publication

Although there is a technique (patent document 2) for adhering to a smooth fluororesin film surface by sputtering, its adoption in actual wiring boards has not progressed due to stability of adhesion during wiring formation and impossibility of practical application to high-speed signal wiring. . As one of the major reasons, the damage to the fluororesin by sputtering and the generation of fluoride by the metal film formed by sputtering and free fluorine are mentioned.

In the case of a copper film by sputtering, a metal film having a thickness of about 0.1 mu m is required for power supply of electrolytic copper plating for wiring formation of a wiring board. Therefore, the surface of the fluororesin is exposed more than necessary to the plasma generated during sputtering, and damage is received. In addition, free fluorine generated at this time is introduced into the metal film formed by sputtering. The damaged fluororesin surface may crack due to slight tension, which may cause wiring breakage. In particular, in the case of a fluororesin film, cracks occur in the fluororesin film only by applying tension through roll processing. Moreover, when the metal film formed by sputtering is copper with a low total loss loss, copper fluoride is formed with time with the free fluorine introduce|transduced into a film|membrane. Copper fluoride is water-soluble, and when dissolved in water, it forms hydrofluoric acid, which corrodes metals. After copper fluoride is formed, corrosion advances in the wet process of wiring formation, and wiring peeling will generate|occur|produce in the metal film part formed by sputtering.

Therefore, the present invention uses a physical vapor deposition method to form a smooth thin copper film on a smooth fluororesin, and by appropriately selecting the type of physical vapor deposition method, secure adhesion strength between the fluororesin and the copper film, and a metal capable of forming wiring The purpose was to produce a picture film.

As a result of intensive studies in view of the above problems, the present inventors have minimized the thickness of the metal film by sputtering and combined the vacuum deposition method to enable electrolytic plating to obtain a metallized film capable of forming wiring with stable adhesion strength reached something

That is, the present invention is a metallized film having a copper film on one or both sides of a fluororesin film, wherein the copper film is composed of two layers of a copper film 1 and a copper film 2 from the side in contact with the fluororesin film, and the copper film 1 is It is a columnar crystal with a film thickness of 10 nm or more and 40 nm or less, and the copper film 2 is a columnar crystal with a film thickness of 0.1 µm or more and 2.0 µm or less.

Further, a metallized film having a metal film on one side or both sides of a fluororesin film, wherein the metal film consists of two layers of a base metal film and a copper film 2 from the side in contact with the fluororesin film, and the base metal film is 1 nm or more and 20 nm or less copper film 2 is a columnar crystal with a film thickness of 0.1 µm or more and 2.0 µm or less, and the metal film is not peeled off by immersion in 200 g/L sulfuric acid for 10 minutes 24 hours after the metal film is formed. it's about

In a preferred embodiment, the copper film 2 relates to a metallized film having a surface roughness Ra of 0.01 µm or more and 0.10 µm or less.

A preferred aspect relates to a metallized film wherein the underlying metal film is any one of nickel, titanium, nickel or an alloy comprising titanium.

A preferred aspect relates to a method for producing a metallized film, wherein the surface of a fluororesin film is subjected to plasma treatment, the copper film 1 is formed by sputtering, and the copper film 2 is formed by vacuum deposition. .

A preferred aspect relates to a method for manufacturing a metallized film, wherein the surface of a fluororesin film is subjected to plasma treatment, the base metal film is formed by sputtering, and the copper film 2 is formed by vacuum deposition.

A preferred aspect relates to a method for manufacturing a fluororesin circuit board, wherein the copper film 3 is formed on the copper film 2 of a metallized film by electrolytic plating to form a wiring circuit.

(Effects of the Invention)

In the present invention, the thickness of the copper metal film by sputtering is controlled to a minimum on the fluororesin film, and the metallized film in which the copper film by the vacuum deposition method is combined does not deteriorate over time and has stable passability of the electrolytic plating process, is smooth and conductive It becomes possible to form a circuit board capable of high-speed signal transmission with low loss.

The present invention will be described in detail below.

The metallized film of the present invention is one in which a copper film is formed on one or both surfaces of a fluororesin film.

It is preferable that the said copper film in this invention consists of two layers of copper film 1 and copper film 2 from the side which is in contact with a fluororesin film, and copper film 1 is formed on such a fluororesin film by sputtering method. In addition, it is preferable to plasma-treat the surface of the fluororesin before forming the copper film 1. Fluorine atoms are stably present on the surface of the fluororesin film to inhibit bonding with metals. Therefore, the fluorine on the surface of the fluororesin film is separated by sputtering or plasma treatment, and a functional group is generated instead, and the adhesion between the functional group and the metal layer is improved by the polarity and reactivity of the functional group. However, when performing sputtering or plasma treatment, if energy to separate fluorine atoms is continuously applied to the surface of the fluororesin, the surface of the fluororesin is damaged. It is necessary to suppress to the minimum in order to suppress the amount of fluorine deviation to a minimum.

Plasma treatment in the present invention is to modify the surface of the fluororesin film by exposing the fluororesin film as a target object to a discharge obtained by applying a high voltage of direct current or alternating current between the high voltage applying electrode and the counter electrode. 5 Pa or more and 1,000 Pa or less are preferable, and, as for the pressure of the atmosphere to discharge, 10 Pa or more and 100 Pa or less are more preferable. When it is less than 5 Pa, the evacuation device becomes large, and when it is larger than 1,000 Pa, it becomes difficult to start discharge.

In the present invention, the atmosphere for plasma treatment is Ar, N ₂ , He, Ne, CO ₂ , CO, air, water vapor, H ₂ , NH ₃ , C _n H _2n+2 (provided that n=an integer of 1 to 4) Although various gases such as hydrocarbons represented by ) can be used alone or in mixture, the oxygen concentration contained in the atmosphere is preferably 500 ppm or less, and more preferably 300 ppm or less. Since oxygen has a property of inactivating active species such as radicals generated by electric discharge, when the concentration is higher than 500 ppm, the treatment effect may become small or the effect may be lost at all.

Any shape of the high-pressure applying electrode can be used. For example, a rod-shaped one is preferable from the viewpoint of continuously processing the film while conveying it. Although a counter electrode will not specifically limit if a film is made to adhere and can be processed, A drum-shaped electrode which can support film conveyance is preferable. In the case of the drum-shaped electrode, for example, it is preferable to have a diameter of at least twice the diameter of the rod-shaped high-voltage applying electrode. The high voltage applying electrode and the counter electrode do not need to be the same, and when two or more high voltage applying electrodes are used for one counter electrode, it is preferable to save space and increase the processing efficiency. The distance between the electrodes may be appropriately set according to the gas pressure conditions and treatment intensity, and is, for example, in the range of 0.05 to 10 cm.

The treatment intensity is preferably 10 W·min/m 2 or more and 2,000 W·min/m 2 or less, and more preferably 50 W·min/m 2 or more and 1,000 W·min/m 2 or less. Here, the processing power density is a value obtained by dividing the product of the electric power and time applied for discharge by the discharge area, and in the case of processing a long film, it is a value obtained by dividing the input power by the width of the discharge portion and the processing speed of the film. When the processing power density is less than 10 W·min/m2, sufficient energy is not given and the treatment effect may not be obtained.

It is preferable that they are 10 nm or more and 40 nm or less, and, as for the thickness of the copper film 1 in this invention, it is more preferable that they are 10 nm or more and 20 nm or less. When thickness is less than 10 nm, sufficient adhesive force may not be acquired. On the other hand, when the thickness exceeds 40 nm, the surface of the fluororesin is damaged to reduce the flexibility as a film, and cracks occur on the surface of the fluororesin. This crack may propagate through the resin surface and cause disconnection after wiring is formed. This crack occurs after the formation of the copper film 1 and before the formation of the copper film 2 . When the copper film becomes thick, the copper film has strength and no cracks occur. When film shrinkage occurs under the influence of heat or the like from the start of sputtering until the copper film becomes thick, it is considered that a brittle layer is generated on the surface of the film resin and cracks occur. Moreover, in order to introduce|transduce into a film|membrane many fluorine which separated from the fluororesin surface, it is estimated that acid-resistance-weak copper fluoride is formed in a copper film. During the wet process of circuit formation, hydrofluoric acid is generated from copper fluoride, which causes corrosion of the copper film 1. Copper fluoride is not produced in the copper film immediately after film formation, but is formed by reacting fluorine and copper introduced into the metal film with time. When fluorine is introduced into the copper film immediately after film formation, the vicinity of the interface between the copper film and the fluororesin is dissolved by acid immersion for 24 hours or more after film formation, and the copper film is peeled off. When forming a circuit board, it is necessary to be immersed in an electrolytic copper plating solution with a sulfuric acid concentration of about 200 g/L for 10 minutes or more, and acid resistance by immersion for 10 minutes or more with a sulfuric acid concentration of 200 g/L or more is essential. Since the output of the sputtering method is strong and the treatment time is longer, the amount of fluorine introduced into the copper film 1 from damage to the resin increases, the thickness of the copper film 1 is preferably thinner, more preferably 20 nm or less.

On the other hand, in a fluororesin film, when forming the copper film 1 by the sputtering method, more fluorine may be separated. In this case, it is not sufficient just to make the copper film 1 thin, and it is preferable to form a base metal film instead of the copper film 1 also in order to ensure acid resistance with a sulfuric acid concentration of 200 g/L. As a base metal film, it is preferable to have corrosion resistance with respect to fluorine, and nickel, titanium, nickel, or the alloy containing titanium is mentioned. A stainless alloy containing nickel also has strong corrosion resistance to fluorine. These metals are excellent in corrosion resistance by forming a stable passivation layer with respect to fluorine, and nickel is particularly excellent. However, on the other hand, these metals have a large transmission loss compared to copper when high-speed signal transmission is considered. Considering the skin effect in which the electric signal is biased on the surface layer of the wiring with high-speed signals, it is preferable that there is no nickel, titanium, nickel or alloy metal layer of an alloy containing titanium at the interface between the resin and the metal layer in contact with the surface layer of the wiring, and there is a large fluorine gap It is desirable to adapt to the minimum thickness only for fluororesin. At this time, it is preferable that the film thickness of a base metal film is 1 nm or more and 20 nm or less. When the underlying metal film thickness is less than 1 nm, sufficient adhesion may not be obtained. In addition, when the underlying metal film is more than 20 nm, transmission loss increases during high-speed transmission, and the high-speed signal deteriorates, making it impossible to use as a material for circuit boards for transmitting high-frequency digital signals.

It is preferable that the copper film 2 in this invention is formed by the vacuum vapor deposition method with the film thickness of 0.1 micrometer or more and 2.0 micrometers or less. Moreover, it is preferable that the copper film 2 is formed by vacuum vapor deposition to a film thickness of 0.1 micrometer or more and 0.5 micrometer or less. The copper film 2 serves as a power supply layer for electrolytic copper plating during circuit board fabrication. However, when the film thickness is less than 0.1 mu m, the resistance is high, which causes film loss during electroplating pretreatment, non-uniformity in film thickness, and occurrence of non-precipitation in electrolytic plating. On the other hand, when the wiring shape is miniaturized, a semi-additive method advantageous for fine pitch is adopted, and the decrease in the wiring width by etching becomes more than twice that of the electrolytic plating feeding layer. For impedance matching of high-speed signals, wiring width control is to reduce etching non-uniformity, and it is desirable for the copper film 2 to be thinner by design. When the power supply layer is larger than 2.0 mu m, the wiring width reduction due to the etching of the wiring width becomes larger than 4.0 mu m, and the etching non-uniformity accompanying it becomes an obstacle to impedance matching. If the pitch of the line space of the wiring is 100 µm or less, the copper film 2 is preferably 2.0 µm or less, and if the pitch of the line space of the wiring is 50 µm or less, the copper film is preferably 0.5 µm or less.

The copper film 2 is preferably formed by a vacuum vapor deposition method that does not easily damage the fluororesin. The vacuum deposition method in the present invention includes an induction heating deposition method, a resistance heating deposition method, a laser beam deposition method, an electron beam deposition method, and the like. Although any vapor deposition method may be used, the electron beam vapor deposition method is suitably used from a viewpoint of having a high film-forming rate. Unlike the sputtering method, the vacuum deposition method does not separate fluorine from the fluororesin, so there is no damage to the fluororesin other than heat, and fluorine is not introduced into the copper film 2 . When the copper film 2 is formed on the underlying metal layer by vacuum deposition, since fluorine is not introduced into the copper film, copper fluoride is not generated, and the acid resistance is improved 24 hours after the film is formed. Since fluorine is not introduced, copper fluoride is not produced even after 24 hours or more, and even if immersed in a sulfuric acid concentration of 200 g/L for 10 minutes or more, the metal film composed of the underlying metal film and the copper film 2 is not peeled off. On the other hand, when the copper film 2 is formed by the sputtering method, even on the underlying metal film, fluorine is separated by damage to the fluororesin, penetrates the underlying metal film and is introduced into the copper film 2, and copper fluoride is produced by the change with time. and the acid resistance decreases. At this time, the copper film 2 will peel by immersion for 10 minutes in 200 g/L of sulfuric acid concentration 24 hours after film-forming.

During vapor deposition, in order not to cause heat damage, vapor deposition is performed while cooling the fluororesin film. When the fluororesin film is sufficiently cooled so that the temperature of the film surface can be kept low, the copper film 1 formed by the sputtering method and the copper film 2 formed by the vacuum deposition method together become columnar crystals.

It is known that the crystal structure of the metal film formed by the sputtering method and the metal film formed by the vacuum deposition method depends on the film formation temperature. In general, assuming that the melting point Tm of the metal film and the film formation temperature Td are Td<0.7Tm, the metal film to be formed becomes a columnar crystal. Since the melting point of copper is 1083°C, if the film formation temperature is sufficiently lower than 758°C, which is 0.7 Tm, the copper film has a columnar crystal structure. Since the film formation temperature of the copper film is considered to be almost the same as the temperature on the fluororesin film, it can be confirmed that the temperature on the fluororesin film can be kept sufficiently low because the copper film is a columnar crystal, so that heat damage can be reduced. Regarding the crystal structure, it is possible to observe the cross-sectional area of the metal film by using the EBSD (Electron Backscattered Diffraction) method. Moreover, when the fluororesin film does not shrink or deform|transform large by heat at the time of film-forming of a copper film, it cools sufficiently, and the crystal structure becomes a structure of columnar crystal|crystallization.

In the present invention, forming a copper film on a fluororesin film by a roll-to-roll method by vacuum deposition is preferably exemplified. In that case, the film is exposed to heat during deposition. The film is cooled by the cooling roll that is in contact with the back surface, but at this time, if the heat resistance temperature of the film is low or the thermal shrinkage of the film is large, the film will float from the cooling roll due to the deformation of the film, so cooling is not sufficient and holes are formed by melting. Empty it or do it. Therefore, a film with a high heat resistance temperature and small heat shrinkage is preferable. It is assumed that the temperature on the film at the time of vapor deposition at the time of forming a copper film by the electron beam method is about 100-120 degreeC. For this reason, it is preferable that a heat-resistant temperature is 120 degreeC or more, and the thermal contraction rate in 120 degreeC is 2.0 % or less in both the longitudinal direction (it is also called MD direction) and the width direction (it is also called TD direction) of a film. When the thermal contraction rate of the film exceeds 2.0%, it is difficult to control the deformation of the fluororesin film by changing the tension or cooling the roll, and when trying to form the thickness of the copper layer, the fluororesin film moves away from the roll and the temperature of the film decreases. It rises and melts, and there exists a possibility that a hole may become empty. More preferably, it is 1.8 % or less of thermal contraction rate, More preferably, it is 1.5 % or less. The thermal shrinkage rate of a fluororesin film can be calculated|required from the dimensional change rate before and after processing at predetermined temperature for 30 minutes.

The fluororesin film suitably used in the present invention is, for example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA), or tetrafluoroethylene-hexafluoropropylene. copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE) can Among these resins, ETFE, PFA, and FEP are preferable from the viewpoint of obtaining a highly heat-resistant film. These fluororesin films may be used independently, and what combined films other than a fluororesin may be used. Moreover, you may use what coated resin, an adhesive, etc. on the film surface, and you may use what has a mold release layer. Moreover, you may use it by bonding together to the surface on which the fluororesin film is not vapor-deposited to the 5-50 micrometers thick polyethylene terephthalate (it may abbreviate as PET) as a carrier as a mold release layer.

Moreover, it is preferable that the thickness of such a fluororesin film is 4 micrometers or more and 75 micrometers or less. If the thickness of the film is less than 4 mu m, the film may be deformed or broken due to the stress generated during deposition. Moreover, when it exceeds 75 micrometers, a film becomes unable to control by tension|tensile_strength, and there is a possibility that winding shift|offset|difference etc. may arise, Moreover, the quantity which can be injected|thrown-in by one vapor deposition will decrease, and productivity will deteriorate. More preferably, they are 6 micrometers or more and 75 micrometers or less.

Moreover, it is preferable that the surface roughness Ra of the metallization film of this invention of a copper film is 0.01 micrometer or more and 0.10 micrometer or less. When the surface becomes rough, transmission loss becomes large due to the skin effect of high-speed signals when wiring of a circuit board is formed, which is not preferable. More preferably, surface roughness Ra is 0.01 micrometer or more and 0.08 micrometer or less, More preferably, surface roughness Ra is 0.01 micrometer or more and 0.06 micrometer or less.

In addition, the metallized film of the present invention can be used for circuit materials, touch panels, and the like.

In addition, this invention is not limited to each structure demonstrated above, Various changes are possible, It is also included in the technical scope of this invention about embodiment obtained by combining the technical means disclosed in each other embodiment suitably.

Example

Hereinafter, the present invention will be specifically described based on Examples, but the present invention is not limited by these Examples.

(Embodiment 1 of wiring formation using metallized film)

A plating resist was formed on the copper film 2 of the metallized film of the present invention. As a plating resist, "PMER P-LA900PM" of TOKYO OHKA KOGYO CO., LTD. was used to form a plating resist having a wiring pattern of L/S = 10/10 µm with a resist thickness of 20 µm. The electrolytic Cu plating solution was copper sulfate pentahydrate 50 g/L, sulfuric acid 200 g/L, chlorine 50 ppm, Meltex Inc. additive "COPPER GLEAM" ST-901A 2 ml/L, "COPPER GLEAM" ST-901B 20 ml/L. . The plating conditions were a jet method, a current density of 1.0 A/dm ² , and the thickness of the copper film 3 was 10 µm. After electroplating, the plating resist was removed with an alkaline stripper, and then the copper film 1 and the copper film 2 for the purpose of power feeding between the wirings were removed using a hydrogen peroxide-sulfuric acid type etchant to form wiring.

In addition, when a metallized film formed with a metal film containing nickel or titanium is used as the underlying metal film, since the underlying metal film is difficult to remove with a hydrogen peroxide-sulfuric acid-based etchant, the copper film 2 is removed by etching, followed by MEC Co., Ltd., Ltd.'s "MEC REMOVER" was used to remove the underlying metal film.

About implementation evaluation of wiring formation, it evaluated in this Embodiment 1, what was able to form wiring was made into (circle), and what was not able to form wiring was made into *.

(Embodiment 2 of wiring formation using metallized film)

Using the same electrolytic plating solution as in Embodiment 1 of wiring formation, the plating condition is a fractionation method, a current density of 1.0 A/dm ² , a copper film 2 of a metallized film of a fluororesin film 2 A copper film 3 with a thickness of 15 μm on the entire surface has formed

Next, an etching resist was formed on the copper film 3 above. As a plating resist, "PMER P-LA900PM" of TOKYO OHKA KOGYO CO., LTD. was used, and the etching resist of the wiring pattern of L/S=50/50 micrometers was formed with the resist thickness of 20 micrometers. After formation of the plating resist, the copper film 1, the copper film 2, and the copper film 3 were etched by a shower method using a ferric chloride-based etching solution. After etching, the etching resist was removed with an alkaline stripper to form wiring.

(Measurement of surface roughness)

The surface roughness Ra is of the arithmetic mean roughness defined in JIS B0601-1994, subtracted from the roughness curve by the reference roughness l in the direction of the average line, and the X-axis in the direction of the average line of this extracted portion, and the direction perpendicular to the X-axis It is a value obtained by the following equation when the Y axis is taken as y = f(x) and the roughness curve is expressed as y = f(x).

The film and copper foil with a release film were surface-observed using the laser microscope (The product made by KEYENCE CORPORATION, VK-8500), and it was performed based on JISB0601-1994. Analysis was performed using analysis application software VK-H1W manufactured by KEYENCE CORPORATION, and the cutoff value was set to 0.25 µm. In the software described above, the surface roughness Ra was obtained by specifying a length of 100 µm. The measurement was carried out in one direction with the sample and the direction perpendicular to that, and the larger value was defined as the surface roughness Ra.

(Measurement of thickness of copper layer)

The thickness of the copper film 2 to a fluororesin film was measured with the fluorescent X-ray film thickness meter (SSI Nanotechnology make, SFT9400).

(thickness of sputtered metal layer)

Measure the transmittance of the sputtered metal layer formed on the transparent PET film with a transmittance meter, and from the obtained value, Lambert-Beer's law

The film thickness was calculated from Here, I ₀ is the amount of light before passing through the thin film, I is the amount of light after passing through the thin film, α is the extinction coefficient, Z is the film thickness, k is the extinction coefficient, and λ is the wavelength. I/I ₀ was a transmittance|permeability, and the value of 2.5765 for copper and 3.2588 for nickel was employ|adopted for the extinction coefficient at the time of wavelength 555 nm, and it was set as the film thickness of the sputtering metal layer.

(Adhesive strength with resin)

The copper film 2 of the metallization film produced with the fluororesin film was plated, and the copper thickness was made into the copper thickness of up to 10 micrometers. Then, the sample was cut out to 10 mm width, and the copper film side was fixed to the acrylic board with double-sided tape. Thereafter, the fluororesin was removed with a tensilon tester at a speed of 50 mm/min, and the adhesion strength was measured. Adhesive strength made 0.5 N/mm or more into (circle) in the range with good adhesive strength, and (circle) in the range with sufficient adhesive strength for the range of 0.4 N/mm or more and less than 0.5 N/mm.

(acid resistance evaluation)

The following acid resistance confirmation tests were implemented as plating process passability evaluation. Evaluation is performed with a metallized film in which time has passed for 24 hours or more after production. Copper fluoride, which reduces acid resistance due to passability through the plating process, is not generated in the copper film immediately after film formation, but is formed by reacting fluorine and copper introduced into the metal film over time. do. With the copper film 2 of the metallized film made of the fluororesin film as the upper surface, from the top, using a cutter knife, insert 6 sheaths in a straight line at a pitch of 2 mm, and in a straight line at a pitch of 2 mm to cross the sheath 90 in a straight line. Insert 6 sheaths into the shape and cross cutter into a dice-shaped shape. At this time, the metal films (base metal film, copper film 1, copper film 2) are completely cut off. The metal film which carried out cross-cutting was immersed in 200 g/L of sulfuric acid for 10 minutes, and what the metal film did not peel has acid resistance, it evaluated that there existed plating process passability, and it was set as (circle). What the metal film peeled during immersion was made into the impossibility of passing through a plating process, and it was set as x.

(check for cracks)

The copper film 2 of the produced metallization film was confirmed with the optical microscope (50 times). The thing in which the crack which spanned the whole visual field of the optical microscope generate|occur|produced in the copper film 2 was made into (circle) that x and the thing which a crack did not generate|occur|produce.

(Example 1)

Plasma treatment was performed on one side of a 75 μm-thick FEP film (manufactured by Toray Advanced Film Co., Ltd., “Toyoflon (registered trademark)”). Plasma treatment conditions were Ar/CH ₄ /CO ₂ mixed gas atmosphere under a pressure of 50 Pa. , the treatment intensity was 500 W min/m 2 . Next, on the surface of the plasma-treated FEP film, a 10 nm thick copper film 1 was formed by magnetron sputtering. As sputtering conditions, a target of 50 mm × 550 mm size is used, and argon gas is The vacuum reached was 1 × 10 ^-2 Pa or less, and the sputtering output was 5 kw using a DC power supply.Then, copper was deposited on the copper film 1 by electron beam evaporation at a film-forming rate of 2.0 μm·m/min, line A copper film 2 was vacuum-deposited to a thickness of 0.5 µm at a speed of 4.0 m/min to obtain a metallized film.

The adhesion strength of this metallized film was 0.40 N/mm, evaluation was ○, crack did not generate|occur|produce, acid resistance was ○, and surface roughness Ra was 0.05 micrometer. Although wiring formation was implemented in both wiring formation embodiment 1 and wiring formation embodiment 2 using this metallization film, wiring formation was possible without any problem in particular.

(Example 2)

Plasma treatment was performed on one side of a 75 µm-thick FEP film (manufactured by Toray Advanced Film Co., Ltd., "Toyoflon (registered trademark)"). As the plasma treatment, it was carried out under the same conditions as in Example 1. Next, the copper film A metallized film was obtained under the same conditions as in Example 1 except that 1 was formed to a thickness of 20 nm.

The adhesion strength of this metallized film was 0.51 N/mm, evaluation was (double-circle), a crack did not generate|occur|produce, acid resistance was (circle), and surface roughness Ra was 0.05 micrometer. Although wiring formation was implemented in both wiring formation embodiment 1 and wiring formation embodiment 2 using this metallization film, wiring formation was possible without any problem in particular.

(Example 3)

Plasma treatment was performed on one side of a 75 µm-thick FEP film (manufactured by Toray Advanced Film Co., Ltd., "Toyoflon (registered trademark)"). As the plasma treatment, it was carried out under the same conditions as in Example 1. Next, the copper film A metallized film was obtained under the same conditions as in Example 1 except that 1 was formed to a thickness of 40 nm.

The adhesion strength of this metallized film was 0.52 N/mm, evaluation was (double-circle), a crack did not generate|occur|produce, acid resistance was (circle), and surface roughness Ra was 0.05 micrometer. Although wiring formation was implemented in both wiring formation embodiment 1 and wiring formation embodiment 2 using this metallization film, wiring formation was possible without any problem in particular.

(Example 4)

Plasma treatment was performed on one side of a 75 µm-thick FEP film (manufactured by Toray Advanced Film Co., Ltd., “Toyoflon (registered trademark)”). As plasma treatment, it was carried out under the same conditions as in Example 1. Next, plasma treatment A 20 nm thick copper film 1 was formed on the surface of one FEP film by magnetron sputtering, a target of size 50 mm × 550 mm was used as the sputtering condition, and the degree of vacuum reaching into which argon gas was introduced was 1 × 10 ^-2 Pa or less, sputtering output 5 kw was adopted using a DC power supply. Next, copper film 2 was vacuum deposited on the copper film 1 by electron beam evaporation to a thickness of 0.1 µm at a film formation rate of 2.0 µm·m/min and a line rate of 20 m/min. Thus, a metallized film was obtained.

The adhesion strength of this metallized film was 0.50 N/mm, evaluation was (double-circle), a crack did not generate|occur|produce, acid resistance was (circle), and surface roughness Ra was 0.05 micrometer. Although wiring formation was implemented in both wiring formation embodiment 1 and wiring formation embodiment 2 using this metallization film, wiring formation was possible without any problem in particular.

(Example 5)

Plasma treatment was performed on one side of a 50 μm thick PFA film (manufactured by DAIKIN INDUSTRIES, LTD., “NEOFLON (registered trademark)”). As the plasma treatment, it was carried out under the same conditions as in Example 1. Next, the plasma-treated PFA film A metallized film was obtained by forming the copper film 1 and the copper film 2 under the same conditions as in Example 2.

The adhesion strength of this metallized film was 0.55 N/mm, evaluation was (double-circle), a crack did not generate|occur|produce, acid resistance was (circle), and surface roughness Ra was 0.08 micrometer. Although wiring formation was implemented in both wiring formation embodiment 1 and wiring formation embodiment 2 using this metallization film, wiring formation was possible without any problem in particular.

(Example 6)

Plasma treatment was performed on one side of a 75 µm-thick FEP film (manufactured by Toray Advanced Film Co., Ltd., “Toyoflon (registered trademark)”). As plasma treatment, it was carried out under the same conditions as in Example 1. Next, plasma treatment A 20 nm thick copper film 1 was formed on the surface of one FEP film by magnetron sputtering, a target of size 50 mm × 550 mm was used as the sputtering condition, and the degree of vacuum reaching into which argon gas was introduced was 1 × 10 ^-2 Pa or less, sputtering output 5 kw was used using a DC power supply. Next, copper film 2 was vacuum-deposited on the copper film 1 to a thickness of 2.0 µm at a deposition rate of 2.0 µm·m/min and a line rate of 1 m/min by electron beam evaporation. Thus, a metallized film was obtained.

The adhesion strength of this metallized film was 0.51 N/mm, evaluation was (double-circle), a crack did not generate|occur|produce, acid resistance was (circle), and surface roughness Ra was 0.05 micrometer. When the wiring formation Embodiment 1 was formed using this metallized film, although the part in which the wiring width narrowed to 4-3 micrometers by etching generate|occur|produced, wiring formation was finally possible. In the wiring formation in Embodiment 2, wiring formation was possible without any problem in particular.

(Example 7)

Plasma treatment was performed on one side of an ETFE film (manufactured by Toray Advanced Film Co., Ltd., "Toyoflon (registered trademark)") having a thickness of 50 µm. The plasma treatment was carried out under the same conditions as in Example 1. Next, in Examples A copper film 1 and a copper film 2 were formed under the same conditions as in 1 to obtain a metallized film.

In this metallized film, the copper 1 melt|dissolved at the time of electrolytic copper plating, the copper film 2 peeled, and adhesive strength was not measurable. Although no cracks occurred, the acid resistance was x and the surface roughness Ra was 0.03 µm. Since copper film peeling occurred at the time of electrolytic copper plating, wiring formation was impossible using this metallized film.

(Example 8)

Plasma treatment was performed on one side of a 50 µm thick ETFE film (manufactured by Toray Advanced Film Co., Ltd., "Toyoflon (registered trademark)"). The plasma treatment was performed under the same conditions as in Example 1. Plasma treatment FEP On the surface of the film, a 1 nm thick nickel film is formed as a base metal film by magnetron sputtering.As the sputtering conditions, a target of size 50 mm × 550 mm is used, and the degree of vacuum reach by introducing argon gas is 1 × 10 ^-2 Pa or less, sputtering output was adopted using a DC power supply of 5 kw.Then, a copper film 2 was formed on the nickel film under the same conditions as in Example 2 to obtain a metallized film.

The adhesion strength of this metallized film was 0.40 N/mm, evaluation was ○, crack did not generate|occur|produce, acid resistance was ○, and surface roughness Ra was 0.03 micrometer. Although wiring formation was implemented in both wiring formation embodiment 1 and wiring formation embodiment 2 using this metallization film, wiring formation was possible without any problem in particular.

(Example 9)

Plasma treatment was performed on one side of a 50 µm thick ETFE film (manufactured by Toray Advanced Film Co., Ltd., "Toyoflon (registered trademark)"). The plasma treatment was performed under the same conditions as in Example 1. Plasma treatment FEP A copper film 2 was formed on the nickel film under the same conditions as in Example 8 except that a nickel film to a thickness of 20 nm was formed as a base metal film on the surface of the film by magnetron sputtering to obtain a metallized film.

The adhesion strength of this metallized film was 0.41 N/mm, evaluation was ○, crack did not generate|occur|produce, acid resistance was ○, and surface roughness Ra was 0.03 micrometer. Although wiring formation was implemented in both wiring formation embodiment 1 and wiring formation embodiment 2 using this metallization film, wiring formation was possible without any problem in particular.

(Example 10)

Plasma treatment was performed on one side of a 50 µm thick ETFE film (manufactured by Toray Advanced Film Co., Ltd., "Toyoflon (registered trademark)"). The plasma treatment was performed under the same conditions as in Example 1. Plasma treatment FEP A copper film 2 was formed on the nickel film under the same conditions as in Example 8 except that a nickel film to a thickness of 0.5 nm was formed as a base metal film by magnetron sputtering on the surface of the film to obtain a metallized film.

In this metallized film, copper melt|dissolved at the time of electrolytic copper plating, the copper film 2 peeled, and adhesive strength was not measurable. Although no cracks occurred, the acid resistance was x and the surface roughness Ra was 0.03 µm. Since copper film peeling occurred at the time of electrolytic copper plating, wiring formation was impossible using this metallized film.

(Example 11)

Plasma treatment was performed on one side of a 50 µm thick ETFE film (manufactured by Toray Advanced Film Co., Ltd., "Toyoflon (registered trademark)"). The plasma treatment was performed under the same conditions as in Example 1. Plasma treatment FEP A copper film 2 was formed on the nickel film under the same conditions as in Example 8 except that a nickel film to a thickness of 25 nm was formed as a base metal film on the surface of the film by magnetron sputtering to obtain a metallized film.

The adhesion strength of this metallized film was 0.41 N/mm, evaluation was ○, crack did not generate|occur|produce, acid resistance was ○, and surface roughness Ra was 0.03 micrometer. Although wiring formation was implemented in both wiring formation embodiment 1 and wiring formation embodiment 2 using this metallization film, wiring formation was possible without any problem in particular.

However, this wiring is higher than the thickness of the nickel film of 20 nm, and the conduction loss of high-speed signal transmission is large, which tends to be more unsuitable for high-frequency applications.

(Example 12)

Plasma treatment was performed on one side of a 75 µm-thick FEP film (manufactured by Toray Advanced Film Co., Ltd., “Toyoflon (registered trademark)”). As plasma treatment, it was carried out under the same conditions as in Example 1. Next, plasma treatment A 20 nm thick copper film 1 was formed on the surface of one FEP film by magnetron sputtering, a target of size 50 mm × 550 mm was used as the sputtering condition, and the degree of vacuum reaching into which argon gas was introduced was 1 × 10 ^-2 Pa or less, sputtering output 5 kw was adopted using a silver DC power supply Then, on the copper film 1, a copper film 2 was subsequently formed to a thickness of 0.1 µm by sputtering under the same conditions to obtain a metallized film.

In this metallized film, the copper 1 and the copper film 2 were melt|dissolved at the time of electrolytic copper plating, the electrolytic copper plating film|membrane peeled, and adhesive strength was not measurable. Although no cracks occurred, the acid resistance was x and the surface roughness Ra was 0.05 µm. Since copper film peeling occurred at the time of electrolytic copper plating, wiring formation was impossible using this metallized film.

(Example 13)

Plasma treatment was performed on one side of a 50 µm thick ETFE film (manufactured by Toray Advanced Film Co., Ltd., "Toyoflon (registered trademark)"). The plasma treatment was performed under the same conditions as in Example 1. Plasma treatment FEP A titanium film 1 nm thick as a base metal film was formed on the surface of the film by magnetron sputtering.As the sputtering conditions, a target of size 50 mm × 550 mm is used, and the degree of vacuum reach by introducing argon gas is 1 × 10 ^-2 Pa or less, sputtering output was adopted using a DC power supply of 5 kw. Next, a copper film 2 was formed on the titanium film under the same conditions as in Example 2 to obtain a metallized film.

The adhesion strength of this metallized film was 0.40 N/mm, evaluation was ○, crack did not generate|occur|produce, acid resistance was ○, and surface roughness Ra was 0.03 micrometer. Although wiring formation was implemented in both wiring formation embodiment 1 and wiring formation embodiment 2 using this metallization film, wiring formation was possible without any problem in particular.

(Example 14)

Plasma treatment was performed on one side of a 50 µm thick ETFE film (manufactured by Toray Advanced Film Co., Ltd., "Toyoflon (registered trademark)"). The plasma treatment was performed under the same conditions as in Example 1. Plasma treatment FEP A copper film 2 was formed on the titanium film under the same conditions as in Example 13 except that a titanium film to a thickness of 20 nm was formed as a base metal film on the surface of the film by magnetron sputtering to obtain a metallized film.

The adhesion strength of this metallized film was 0.40 N/mm, evaluation was ○, crack did not generate|occur|produce, acid resistance was ○, and surface roughness Ra was 0.03 micrometer. Although wiring formation was implemented in both wiring formation embodiment 1 and wiring formation embodiment 2 using this metallization film, wiring formation was possible without any problem in particular.

(Example 15)

Plasma treatment was performed on one side of a 50 µm thick ETFE film (manufactured by Toray Advanced Film Co., Ltd., "Toyoflon (registered trademark)"). The plasma treatment was performed under the same conditions as in Example 1. Plasma treatment FEP A copper film 2 was formed on the titanium film under the same conditions as in Example 13 except that a titanium film to a thickness of 0.5 nm was formed as a base metal film on the surface of the film by magnetron sputtering to obtain a metallized film.

In this metallized film, copper melt|dissolved at the time of electrolytic copper plating, the copper film 2 peeled, and adhesive strength was not measurable. Although no cracks occurred, the acid resistance was x and the surface roughness Ra was 0.03 µm. Since copper film peeling occurred at the time of electrolytic copper plating, wiring formation was impossible using this metallized film.

(Example 16)

Plasma treatment was performed on one side of a 50 µm thick ETFE film (manufactured by Toray Advanced Film Co., Ltd., "Toyoflon (registered trademark)"). The plasma treatment was performed under the same conditions as in Example 1. Plasma treatment FEP A copper film 2 was formed on the titanium film under the same conditions as in Example 13 except that a titanium film to a thickness of 25 nm was formed as a base metal film on the surface of the film by magnetron sputtering to obtain a metallized film.

The adhesion strength of this metallized film was 0.40 N/mm, evaluation was ○, crack did not generate|occur|produce, acid resistance was ○, and surface roughness Ra was 0.03 micrometer. Although wiring formation was implemented in both wiring formation embodiment 1 and wiring formation embodiment 2 using this metallization film, wiring formation was possible without any problem in particular.

However, this wiring is higher than the thickness of the titanium film of 20 nm, the conduction loss of high-speed signal transmission becomes large, and it tends to be more unsuitable for high-frequency applications.

(Comparative Example 1)

Plasma treatment was performed on one side of a 75 µm-thick FEP film (manufactured by Toray Advanced Film Co., Ltd., “Toyoflon (registered trademark)”). As plasma treatment, it was carried out under the same conditions as in Example 1. Next, plasma treatment A copper film 2 was vacuum-deposited on the surface of one FEP film to a thickness of 0.5 μm at a deposition rate of 2.0 μm·m/min and a line speed of 4.0 m/min by electron beam evaporation to obtain a metallized film.

Although electrolytic copper plating of this metallized film was possible, the adhesion strength was very small, copper foil peeling generate|occur|produced with the sample weight, and measurement was impossible. Although a crack did not generate|occur|produce, since peeling generate|occur|produced at the time of cross-cutting and it peeled before acid immersion, acid resistance was set as x. The surface roughness Ra was 0.05 mu m. Since copper film peeling occurred in the etching process of wiring formation, wiring formation was impossible using this metallization film.

(Comparative Example 2)

Plasma treatment was performed on one side of a 75 µm-thick FEP film (manufactured by Toray Advanced Film Co., Ltd., "Toyoflon (registered trademark)"). As the plasma treatment, it was carried out under the same conditions as in Example 1. Next, the copper film A metallized film was obtained under the same conditions as in Example 1 except that 1 was formed to a thickness of 5 nm.

The adhesion strength of this metallized film was 0.26 N/mm, evaluation was x, a crack did not generate|occur|produce, acid resistance was (circle), and surface roughness Ra was 0.05 m. Although wiring formation was implemented in both wiring formation embodiment 1 and wiring formation embodiment 2 using this metallization film, wiring formation was possible without any problem in particular.

(Comparative Example 3)

Plasma treatment was performed on one side of a 75 µm-thick FEP film (manufactured by Toray Advanced Film Co., Ltd., "Toyoflon (registered trademark)"). As the plasma treatment, it was carried out under the same conditions as in Example 1. Next, the copper film A metallized film was obtained under the same conditions as in Example 1 except that 1 was formed to a thickness of 50 nm.

In this metallized film, the copper 1 melt|dissolved at the time of electrolytic copper plating, the copper film 2 peeled, and adhesive strength was not measurable. Although no cracks occurred, the acid resistance was x and the surface roughness Ra was 0.05 µm. Since copper film peeling occurred at the time of electrolytic copper plating, wiring formation was impossible using this metallized film.

(Comparative Example 4)

Plasma treatment was performed on one side of a 75 µm-thick FEP film (manufactured by Toray Advanced Film Co., Ltd., “Toyoflon (registered trademark)”). As plasma treatment, it was carried out under the same conditions as in Example 1. Next, plasma treatment A 20 nm thick copper film 1 was formed on the surface of one FEP film by magnetron sputtering, a target of size 50 mm × 550 mm was used as the sputtering condition, and the degree of vacuum reaching into which argon gas was introduced was 1 × 10 ^-2 Pa or less, sputtering output 5 kw was adopted using a silver DC power supply Then, copper film 2 was vacuum deposited on the copper film 1 by electron beam deposition to a thickness of 0.05 µm at a film formation rate of 2.0 µm·m/min and a line speed of 40 m/min. Thus, a metallized film was obtained.

Since the copper film 1 and the copper film 2 of this metallization film are thin, they have high resistance as a power feeding layer for electrolytic plating, and the electrolytic copper plating did not precipitate, but was partially etched by the plating solution to lose the film. No cracks occurred, acid resistance was ?, and surface roughness Ra was 0.05 µm. An attempt was made to form wiring in both of the wiring formation embodiment 1 and the wiring formation embodiment 2 using this metallized film, but since electrolytic copper plating could not be performed, wiring formation was impossible.

(Comparative Example 5)

Plasma treatment was performed on one side of a 75 µm-thick FEP film (manufactured by Toray Advanced Film Co., Ltd., “Toyoflon (registered trademark)”). As plasma treatment, it was carried out under the same conditions as in Example 1. Next, plasma treatment A 20 nm thick copper film 1 was formed on the surface of one FEP film by magnetron sputtering, a target of size 50 mm × 550 mm was used as the sputtering condition, and the degree of vacuum reaching into which argon gas was introduced was 1 × 10 ^-2 Pa or less, sputtering output 5 kw was used using a DC power supply. Then, copper was deposited on the copper film 1 by electron beam evaporation at a deposition rate of 2.0 µm·m/min and a line rate of 0.7 m/min, and the copper film 2 was vacuumed to a thickness of 3.0 µm. A metallized film was obtained by vapor deposition.

The adhesion strength of this metallized film was 0.50 N/mm, evaluation was (double-circle), a crack did not generate|occur|produce, acid resistance was (circle), and surface roughness Ra was 0.05 micrometer. When the wiring formation Embodiment 1 was formed using this metallized film, the part in which wiring width was lose|disappeared by etching generate|occur|produced, and wiring formation was impossible. In the wiring formation in Embodiment 2, wiring formation was possible without any problem in particular.

(Comparative Example 6)

Plasma treatment was performed on one side of a 75 µm-thick FEP film (manufactured by Toray Advanced Film Co., Ltd., “Toyoflon (registered trademark)”). As plasma treatment, it was carried out under the same conditions as in Example 1. Next, plasma treatment On the surface of one FEP film, a nickel film is formed as a base metal film with a thickness of 1 nm by magnetron sputtering.As the sputtering conditions, a target of size 50 mm × 550 mm is used, and the degree of vacuum reach by introducing argon gas is 1 × 10 ^-2 Pa or less, The sputtering output is 5 kw using DC power supply.Then, on the base metal layer, by magnetron sputtering method, a copper film 2 is formed into a film with a thickness of 0.1 μm to obtain a metallized film. As a copper film 2 sputtering condition, the size of 50 mm × 550 mm The target was used and the degree of vacuum reaching into which argon gas was introduced was 1×10 ^-2 Pa or less, and the sputtering output was 5 kw using a DC power supply.

In this metallized film, the copper film 2 was melt|dissolved at the time of electrolytic copper plating, the electrolytic copper plating film|membrane peeled, and adhesive strength was not measurable. Although no cracks occurred, the acid resistance was x and the surface roughness Ra was 0.03 µm. Since copper film peeling occurred at the time of electrolytic copper plating, wiring formation was impossible using this metallized film.

[Table 1-1]

[Table 1-2]

[Table 1-3]

[Table 2-1]

[Table 2-2]

[Table 2-3]

Claims (7)

A metallized film having a metal film on one side or both sides of a fluororesin film for performing electrolytic plating necessary for wiring formation, the metallized film comprising:
The metal film consists of two layers of a base metal film and a copper film 2 from the side in contact with the fluororesin film,
The underlying metal film has a film thickness of 1 nm or more and 20 nm or less, and the copper film 2 is a columnar crystal having a film thickness of 0.1 µm or more and 2.0 µm or less,
The metal film does not peel off by immersion in 200 g/L sulfuric acid for 10 minutes 24 hours after the metal film is formed, and the adhesion strength after plating the copper film 2 to make the copper thickness 10 µm is 0.4 N/m or more, metallization film. A metallized film having a metal film on one side or both sides of a fluororesin film for performing electrolytic plating necessary for wiring formation, the metallized film comprising:
The metal film consists of two layers of a base metal film and a copper film 2 from the side in contact with the fluororesin film,
The underlying metal film has a film thickness of 1 nm or more and 20 nm or less, and the copper film 2 is a columnar crystal having a film thickness of 0.1 µm or more and 2.0 µm or less,
The metal film is not peeled off by immersion in 200 g/L sulfuric acid for 10 minutes 24 hours after the metal film is formed, and the adhesion strength after plating the copper film 2 to make the copper thickness 10 µm is 0.4 N/m or more, copper A metallized film with electrolytic copper plating on top of film 2. 3. The method according to claim 1 or 2,
A metallized film wherein the underlying metal film is any one of nickel, titanium, nickel, or an alloy containing titanium. 3. The method according to claim 1 or 2,
The copper film 2 is a metallized film having a surface roughness Ra of 0.01 µm or more and 0.10 µm or less. A method for producing the metallized film according to claim 1 or 2, wherein the surface of the fluororesin film is subjected to plasma treatment, the base metal film is formed by sputtering, and the copper film 2 is formed by vacuum deposition rather than sputtering. A method for producing a metallized film. A method for manufacturing a fluororesin circuit board using the metallized film according to claim 1 or 2, wherein the copper film 3 is formed on the copper film 2 of the metallized film by electrolytic plating to form a wiring circuit. A method for manufacturing a fluororesin circuit board comprising:
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