JP2007247026A - Two layer film, method for producing two layer film, and method for producing printed board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a two layer film of a high molecule layer and a metal layer in which the metal layer has sufficient adhesive strength even when used for high density printed wiring, to provide its production method, and to provide a method for producing a printed board using the method. <P>SOLUTION: The two layer film is provided with: a high molecule film 10; a first metallic film 12 comprising, by weight, 60 to 100% nickel which is formed on the high molecule film in an atmosphere comprising any one gas selected from ammonia, nitrogen monoxide and nitrogen dioxide by a vacuum deposition process or an ion plating process or a sputtering process; and a second metallic film 14 essentially composed of copper which is formed on the first metallic film 12. The method for producing a two layer film includes: a stage where the nickel-containing first metallic film 12 is formed on a high molecule film in an atmosphere comprising any one gas selected from the group consisting of ammonia, nitrogen monoxide and nitrogen dioxide by a vacuum deposition process or the like; and a stage where the second metallic film essentially composed of copper is formed on the first metallic film. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a two-layer film, a method for producing a two-layer film, and a method for producing a printed circuit board, and more particularly to a two-layer film having high adhesion strength between a metal layer and a polymer layer and a method for producing the same.

  In recent years, with the miniaturization of electrical and electronic products, the conductor width of printed wiring boards and the narrowing, multi-layer, and high density of conductors are progressing. As these substrates, conventionally, insulating materials such as paper / phenol resin impregnation system, paper / epoxy resin impregnation system, glass cloth / epoxy resin impregnation system, and ceramic materials have been often used. These materials have a problem that they are poor in flexibility and are difficult to cope with various uses. For this reason, a flexible printed wiring board in which a copper thin film is formed on a plastic film is used. The plastic film is rich in flexibility and has high insulation properties, and if a thermally stable plastic film such as a polyethylene terephthalate film or a polyimide film is used, the plastic film is thermally strong, and its application is widened. However, the copper thin film formed on the plastic film has a drawback that it is easily peeled off during the manufacturing process and use. Then, in order to increase the adhesive strength of a copper thin film, the proposal etc. which form a copper thin film by sputtering in nitrogen atmosphere are made | formed (refer patent document 1).

Japanese Patent No. 2982851 (paragraphs 0016 and 0017)

  However, the copper thin film formed by the above method has not been able to be said to have sufficient adhesion strength for use in high-density printed wiring. Accordingly, the present invention provides a polymer-metal two-layer film having a sufficient adhesion strength even when used for high-density printed wiring, a method for producing the same, and a method for producing a printed circuit board using the method. The purpose is to provide.

  In order to achieve the above object, a two-layer film according to the invention described in claim 1 includes a polymer film 10 as shown in FIG. 1; ammonia, nitric oxide, and carbon dioxide on the polymer film 10; First metal film 12 containing 60 wt% or more and 100 wt% or less of nickel formed by vacuum deposition, ion plating, or sputtering under an atmosphere containing any one gas of the group consisting of nitrogen And a second metal film 14 mainly formed of copper formed on the first metal film 12.

  According to this structure, nickel formed by vacuum deposition, ion plating, or sputtering under an atmosphere containing any one gas of the group consisting of ammonia, nitric oxide, and nitrogen dioxide is added. The first metal film containing from 100% by weight to 100% by weight acts as an adhesive layer, resulting in a two-layer film having high adhesion strength between the metal film mainly composed of copper and the polymer film.

  Moreover, in order to achieve the said objective, the two-layer film which concerns on invention of Claim 2 is, for example, as shown in FIG. 1, with the polymer film 10; On the polymer film 10, ammonia, nitric oxide, And an atmosphere containing any one gas of the group consisting of nitrogen dioxide and formed by a vacuum deposition method, an ion plating method, or a sputtering method. A first metal film 12 containing 1 atomic% or more and 50 atomic% or less; and a second metal film 14 formed on the first metal film 12 and containing copper as a main component.

  According to this structure, nickel atoms formed by a vacuum deposition method, an ion plating method, or a sputtering method in an atmosphere containing any one gas of the group consisting of ammonia, nitric oxide, and nitrogen dioxide are formed. The first metal film containing 50 atom% to 99 atom% and nitrogen atom 1 atom% to 50 atom% acts as an adhesive layer, and the adhesion strength between the metal film mainly composed of copper and the polymer film It becomes a high two-layer film.

  Further, the two-layer film according to the invention described in claim 3 is the double-layer film according to claim 1 or 2, wherein the adhesion strength between the polymer film 10 and the first metal film 12 is an initial 490N. The adhesion strength after dry heating at 120 ° C. for 240 hours is 294 N / m or more.

  If comprised in this way, even if it uses for a high-density printed wiring board, for example, it will become a two-layer film which has suitable adhesive strength.

  The two-layer film according to the invention described in claim 4 is the two-layer film according to any one of claims 1 to 3, wherein the polymer film 10 is formed of a polymer containing nitrogen atoms. Has been.

  If comprised in this way, since a polymer film contains a nitrogen atom, the adhesiveness with respect to the nickel of a polymer film will go up, and it will become a two-layer film which is easy to process in the process of a two-layer film. For example, it is easy to manufacture a printed circuit board from a two-layer film.

  Moreover, the two-layer film according to the invention described in claim 5 is the two-layer film according to claim 4, wherein the polymer containing nitrogen atoms is composed of polyimide, polyetherimide, polyamideimide, and aramid. Any one of the above.

  When configured in this way, polyimide, polyetherimide, polyamideimide, and aramid are all resistant to high temperatures. For example, when processed into a printed circuit board, a two-layer film that is not easily damaged even when exposed to high temperatures by soldering. Become.

  Further, the two-layer film according to the invention described in claim 6 is the two-layer film according to any one of claims 1 to 5, wherein the thickness of the first metal film 12 is 3 nm or more and 100 nm. The thickness of the second metal film 14 is 20 nm or more and 5000 nm or less.

  With this configuration, the thickness of the first metal film becomes a thickness that provides high adhesion strength, and the thickness of the second metal film increases, for example, the productivity of the subsequent plating process, And since it becomes the thickness of the range which can perform an etching process easily, it becomes a 2 layer film of appropriate thickness.

  In addition, the two-layer film according to the invention described in claim 7 is the second metal film in the two-layer film according to any one of claims 1 to 6, for example, as shown in FIG. A third metal film 16 mainly composed of copper is formed on the electrode 14 by an electrodeposition method or an electroless plating method.

  If comprised in this way, it will become a 2 layer film with a high copper film | membrane with high adhesive strength with a polymer film.

  In order to achieve the above object, a method for producing a two-layer film according to an eighth aspect of the present invention includes, as shown in FIGS. 1 and 2, for example, ammonia, nitric oxide, and carbon dioxide on a polymer film 10. First metal film 12 containing nickel in an amount of 60 wt% or more and 100 wt% or less is formed by vacuum deposition, ion plating, or sputtering in an atmosphere containing any one gas of the group consisting of nitrogen. And a step of forming a second metal film 14 mainly composed of copper on the first metal film 12.

  With this configuration, nickel is added by 60% by weight by a vacuum deposition method, an ion plating method, or a sputtering method in an atmosphere containing any one gas selected from the group consisting of ammonia, nitric oxide, and nitrogen dioxide. Since the first metal film containing 100% by weight or less is formed, the metal layer and the polymer layer are less likely to be peeled off, and a production method in which a stable two-layer film with high adhesion strength is produced uniformly. Furthermore, since the first metal film is formed by a vacuum deposition method, an ion plating method, or a sputtering method, it is a method for producing a two-layer film suitable for industrial production.

  In order to achieve the above object, a method for producing a two-layer film according to a ninth aspect of the present invention includes, for example, as shown in FIG. 1 and FIG. In an atmosphere containing any one gas of the group consisting of nitrogen, nickel atom is 50 atomic% or more and 99 atomic% or less and nitrogen atom is 1 atomic% or more by vacuum deposition method, ion plating method or sputtering method. Forming a first metal film 12 containing 50 atomic% or less; and forming a second metal film 14 mainly composed of copper on the first metal film 12.

According to this configuration, 50 atoms of nickel atoms are formed by vacuum deposition, ion plating, or sputtering in an atmosphere containing any one gas selected from the group consisting of ammonia, nitric oxide, and nitrogen dioxide. Since the first metal film containing no less than 99% and no more than 99% and nitrogen atoms of no less than 1% and no more than 50% is formed, the metal layer and the polymer layer are difficult to peel off, and the two layers have high adhesion strength and are stable. This is a production method in which the film is produced uniformly. Furthermore, since the first metal film is formed by a vacuum deposition method, an ion plating method, or a sputtering method, it is a method for producing a two-layer film suitable for industrial production.

  In order to achieve the above object, a method for manufacturing a printed circuit board according to a tenth aspect of the present invention includes two layers according to the method for manufacturing a two-layer film according to the eighth or ninth aspect, for example, as shown in FIG. A process for producing a film (steps St11 to St13); a process for forming a print pattern on the two-layer film produced by the method for producing a two-layer film (steps St21 to St25); and a two-layer film on which the print pattern is formed And a step of arranging elements (step St41).

  When configured in this way, wiring is performed using a two-layer film in which a polymer film and a metal film having high adhesion strength are formed, and an element is disposed thereon, so that a method for manufacturing a printed circuit board with high wiring strength and Become.

  In the two-layer film according to the present invention, a vacuum deposition method or an ion plate is performed in an atmosphere containing a polymer film and any one gas selected from the group consisting of ammonia, nitric oxide, and nitrogen dioxide on the polymer film. A first metal film containing 60 wt% or more and 100 wt% or less of nickel formed by a plating method or a sputtering method; and a second metal film mainly composed of copper formed on the first metal film. Therefore, the first metal film containing 60 wt% or more and 100 wt% or less of nickel formed in an atmosphere containing any one gas of the group consisting of ammonia, nitric oxide, and nitrogen dioxide acts as an adhesive layer. Thus, a two-layer film having high adhesion strength between the metal layer and the polymer layer is obtained. Moreover, in the two-layer film according to the present invention, a vacuum deposition method or an atmosphere in an atmosphere containing a polymer film and any one gas selected from the group consisting of ammonia, nitric oxide, and nitrogen dioxide on the polymer film. Formed on the first metal film, the first metal film containing nickel atoms formed by ion plating method or sputtering method and containing 50 atom% or more and 99 atom% or less nitrogen atom and 1 atom% or more and 50 atom% or less Since the first metal film acts as an adhesive layer and is used for high-density printed wiring, the adhesion strength between the metal layer and the polymer layer is high. It becomes a two-layer film.

  The method for producing a two-layer film according to the present invention includes a vacuum deposition method or an ion in an atmosphere containing any one gas selected from the group consisting of ammonia, nitric oxide, and nitrogen dioxide on a polymer film. A step of forming a first metal film containing nickel by weight of 60 wt% or more and 100 wt% or less by a plating method or a sputtering method, and forming a second metal film containing copper as a main component on the first metal film. Therefore, the first metal film acts as an adhesive layer, and the method for producing a two-layer film in which the metal layer and the polymer layer are difficult to peel off is obtained. The method for producing a two-layer film according to the present invention includes a vacuum deposition method or an ion in an atmosphere containing any one gas selected from the group consisting of ammonia, nitric oxide, and nitrogen dioxide on a polymer film. Forming a first metal film containing 50 to 99 atomic percent of nickel atoms and 1 to 50 atomic percent of nitrogen atoms by a plating method or a sputtering method; and copper on the first metal film And a step of forming a second metal film as a main component. Therefore, the first metal film acts as an adhesive layer, and a method for producing a two-layer film in which the metal layer and the polymer layer are difficult to peel off. Furthermore, by manufacturing a printed circuit board using the two-layer film manufactured by the above manufacturing method, a printed circuit board manufacturing method in which the metal layer and the polymer layer are difficult to peel off is obtained.

  Embodiments of the present invention will be described below with reference to the drawings. In each figure, the same or equivalent devices are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 (a) shows a cross-sectional view of the two-layer films 1 to 3, which is the first embodiment of the present invention. The two-layer films 1 to 3 are mainly used as a printed wiring board film for producing a printed circuit board. The two-layer film 1 shown in FIG. 1A includes a polymer film 10, a first metal film 12 formed on the polymer film 10, and a second film formed on the first metal film 12. And a metal film 14. Here, the two-layer film 1 includes a polymer film 10, a first metal film 12, and a second metal film 14. However, the one-layer polymer film 10 and the one-layer metal film (first metal film Since it has the film 12 and the second metal film 14), it is called a two-layer film.

  When the polymer film 10 is exposed to a high temperature when forming a metal film thereon, or when a device and a conductor are soldered on a two-layer film and exposed to a high temperature at that time, etc. A polymer film having heat resistance is preferably used. Moreover, it is preferable that it is a polymer | macromolecule which has corrosion resistance with respect to processes, such as an etching at the time of processing into a board | substrate. Polymers containing nitrogen atoms are suitable because they are generally excellent in adhesion. Furthermore, many of them are excellent in heat resistance, and polymer films containing nitrogen atoms are often used preferably. In particular, polyimide, polyetherimide, polyamideimide, aramid, and the like are preferably used because they have high heat resistance. The nitrogen atom is not contained in the molecular structure of the main raw material of the polymer film, and may be contained in the additive. The thickness of the polymer film is 1 μm or more and 500 μm or less, preferably 3 μm or more, more preferably 10 μm or more, preferably 300 μm or less, and more preferably 150 μm or less. When the thickness of the polymer film is too thin, handling for a circuit board becomes difficult, and plating becomes difficult. If the thickness of the polymer film is too thick, it becomes rigid and becomes a two-layer film with no flexibility.

  The first metal film 12 is a film formed on the polymer film 10 and contains 60 wt% or more and 100 wt% or less of nickel containing nitrogen atoms. Here, nickel is generally 60 wt% or more and 100 wt% or less, and the rest is generally copper, titanium, or the like, but is not limited thereto. Further, when the first metal film 12 is detected by, for example, a high resolution Rutherford backscattering spectrometry method (High Resolution Rutherford Backscattering Spectrometry), the nitrogen concentration is 1 atomic% or more and 50 atomic% or less. Preferably it contains 1 atom% or more and 30 atom% or less, more preferably 1 atom% or more and 20 atom% or less. Even if such a nitrogen atom is contained, the influence on the weight% of nickel is negligibly small.

  The first metal film 12 is formed by a vacuum film formation method (hereinafter referred to as a vacuum film formation method) such as a vacuum deposition method, a sputtering method, or an ion plating method, whereby a homogeneous film can be obtained. Therefore, it is preferable. According to these vacuum film formation methods, metal ions ionized in vacuum are deposited on the polymer film to form a film, so that the film material or target from which the metal ions originate contains nitrogen as an impurity. However, since it is removed when ionized, it is generally not contained in the formed metal film. However, by forming a metal film by a vacuum film-forming method in an atmosphere containing any one gas of the group consisting of ammonia, nitric oxide and nitrogen dioxide, nitrogen atoms contained in these gases are formed. Thus, a metal film containing nitrogen atoms is formed. As is clear here, sputtering in this document means that ions of an inert gas such as argon collide with a target such as a metal, and as a result, metal atoms ejected from the target adhere to the adherend (a film is deposited by sputtering). In addition to the phenomenon of adhering to the surface of the material, it refers to sputtering in a broad sense including the following phenomenon. That is, by using gases such as ammonia, nitrogen monoxide, and nitrogen dioxide as reactive gases instead of inert gases, the metal atoms are ejected from the target such as metal, and the reaction between the metal atoms and the gas occurs. And adheres to the surface of the adherend to form a thin film. Such a phenomenon is called reactive sputtering. At this time, nitrogen ions hit the surface of the adherend and the surface is treated with nitrogen ions. Such treatment is called ion bombardment, and these phenomena are sometimes combined and called plasma treatment. According to sputtering, particles with metal atoms and reactive gas ejected by ion collision collide with the adherend, so that the adhesion is likely to increase. The first metal film 12 may be formed by a method other than the vacuum film formation method.

  The first metal film 12 functions as an adhesive layer between the polymer film 10 and the second metal film 14. The thickness of the first metal film 12 is preferably 3 nm to 100 nm. The thickness is preferably 10 nm or more, and preferably 30 nm or less. With such a thickness, the adhesion strength between the polymer film 10 and the first metal film 12 and the second metal film 14 is increased. Specifically, the adhesion strength according to the Japan Printed Circuits Industry Association, JPCA standard “copper-clad laminate for flexible printed wiring boards (adhesive and non-adhesive type)” JPCA-BM03-2003 is initially 490 N / m or more. It is also preferable that it is 294 N / m or more after drying at 120 ° C. for 240 hours. By having this adhesion strength, even if the two-layer film 1 is exposed to heat and exposed to a high temperature, the metal film does not peel off and becomes a two-layer film suitably used for high-density printed wiring.

  The second metal film 14 is formed with copper as a main component. Here, “having copper as the main component” means that the main component is copper, and that the component contains the most copper. Preferably, the copper content is 70% by weight or more, more preferably 90% by weight or more. The second metal film is also preferably formed by a vacuum film forming method because the film is formed homogeneously and densely. The second metal film 14 is processed into a printed wiring, and the thickness is preferably 20 nm or more and 5000 nm or less. Preferably, it is 50 nm or more, and preferably 3000 nm or less. If the second metal film 14 is formed thick, it becomes easy to form a third metal film 16 which will be described later, or the electric conductivity as wiring is improved and stabilized. This is not preferable because it takes time for the film and costs are increased. Furthermore, there is a demerit that the heat at the time of film formation causes deformation such as warping and curling, and the etching at the time of processing into wiring becomes difficult. Therefore, the thickness is preferably in the above range. In order to obtain the above thickness, the second metal film 14 is particularly preferably formed by a vacuum deposition method among the vacuum film forming methods. In the vacuum deposition method, since the metal evaporation rate is high, the film can be formed at a high speed, and a thick film is easily formed. Moreover, since the energy which the evaporation metal particle has is small compared with sputtering, the damage given to a to-be-adhered body is small.

  As shown in the cross-sectional view of FIG. 1B, the two-layer film 2 may have a first metal film 12 and a second metal film 14 on both surfaces of the polymer film 10. By using the two-layer film 2 having the first metal film 12 and the second metal film 14 on both surfaces, the printed wiring can be processed on both surfaces, so that the size of the substrate can be reduced. Also in this case, since it has a single-layer polymer film and a metal film, it is called a two-layer film.

  In addition, as shown in the cross-sectional view of FIG. 1C, the two-layer film 3 may form a third metal film 16 on the second metal film 14. The third metal film 16 is a film containing copper as a main component, is similar in material to the second metal film 14, and has high adhesion strength. Since the third metal film 16 is formed thick, it is preferable to form the third metal film 16 by an electrodeposition (electroplating or electroforming) method or an electroless plating (chemical plating) method. The thickness of the third metal film 16 is preferably 1 μm or more and 100 μm or less. The third metal film 16 is also processed as the wiring of the wiring board.

  Then, with reference to FIG. 2, the manufacturing method of the two-layer film 1 which is the 1st Embodiment of this invention is demonstrated. Note that FIG. 1 is also referred to as appropriate. FIG. 2 is a schematic cross-sectional view of an apparatus for producing a two-layer film 1 in which a first metal film 12 is formed on a polymer film 10 by sputtering in a vacuum chamber 33 and a second metal film 14 is formed by vapor deposition. It is. When the two-layer film 1 is formed by combining other vacuum film forming methods, it can be manufactured by the same method. Moreover, the two-layer film 2 can be manufactured by forming the first metal film 12 and the second metal film 14 on both surfaces of the polymer film 10 using the method described here. Moreover, if the 3rd metal film 16 is formed by electrodeposition or electrodeless plating using the 2 layer film manufactured using the method demonstrated here, the 2 layer film 3 will be manufactured.

  The vacuum chamber 33 is a highly airtight container for keeping the inside vacuum, and is, for example, a cylindrical container having a length of 3 m, a width of 5 m, and a height of 3 m. An intake pipe 34 is connected to the vacuum chamber 33, and the other end is connected to a vacuum pump 35. In the vacuum chamber 33, an original fabric 41 on which the polymer film 10 is wound in a roll shape is installed. The polymer film 10 is guided from the original fabric 41 to the guide roller 32 and reaches the lower portion of the roller 31. The roller 31 has a cylindrical shape and rotates at the same speed in the same direction as the direction in which the polymer film 10 is fed (arrow in FIG. 2). Refrigerant pipes 36 and 37 are connected to the roller 31. The refrigerant pipes 36 and 37 are connected to a refrigerant cooling device (not shown) outside the vacuum chamber 33, from which refrigerant r is supplied into the roller 31 and returned. The roller 31 is cooled by the refrigerant r and kept at a low temperature. The polymer film 10 in contact with the lower surface of the roller 31 is led to the guide roller 32 ′ and wound around the product roller 42.

  Under the roller 31, a container 23 in which the vapor deposition material 24 is stored is installed. The container 23 is configured to be heated by electricity (not shown). Heating by electricity can be performed by heating up to a temperature sufficiently higher than the melting point of the vapor deposition material 24, whether it is electric resistance heating, dielectric heating, high-frequency induction heating, or other heating methods, and can maintain the temperature. Good. As the vapor deposition material 24, copper is preferably used. The gap between the lower portion of the roller 31 and the upper surface of the container 23 varies depending on the type of copper material, temperature conditions, and the like, and is in the range of 1 to several 100 mm, but is not limited to the above range.

  A nickel alloy or nickel (hereinafter referred to as a target) 22 as a sputtering target is disposed on the traveling path of the polymer film 10 between the original fabric 41 and the roller 31. A cathode is connected to the target 22, an anode is connected to the polymer film 10 facing the target 22, and a voltage is applied between these electrodes. Near the target 22 and the polymer film 10, a discharge port 44 of a reaction gas pipe 43 for supplying ammonia gas is provided. The reaction gas pipe 43 supplies ammonia gas near the target 22 from an external ammonia gas supply source. The gas supplied from the reaction gas pipe 43 is not limited to ammonia gas, and may be nitrogen monoxide or nitrogen dioxide, a mixed gas thereof, or a gas containing these gases.

  In order to manufacture the two-layer film 1 using the above-described apparatus, first, the raw fabric 41 is placed in the vacuum chamber 31 and the polymer film 10 is guided to the product roller 42 as described above. Subsequently, after the inside of the vacuum chamber 33 is made airtight, the gas remaining in the vacuum chamber 31 is decompressed by the vacuum pump 35 until the degree of vacuum becomes, for example, 0.667 to 0.00133 Pa.

  By applying a voltage to the electrode between the target 22 and the polymer film 10 under vacuum, the gas in the vacuum chamber 33 is ionized, and the ionized ions collide with the target 22, thereby causing nickel and alloy atoms from the target. Jumps out. The nickel and alloy atoms that have jumped out adhere to the polymer film with nitrogen in the atmosphere gas. This is sputtering. The ammonia gas supplied from the reaction gas pipe 43 is contained at a concentration of 10% by volume or more, and thus nickel formed on the polymer film 10 by performing sputtering in a gas atmosphere containing nitrogen. Alternatively, the nickel alloy film contains nitrogen. When nickel or a nickel alloy contains nitrogen, adhesion with the polymer film 10 is enhanced.

  Further, the container 23 storing the copper 24 as a vapor deposition material is heated, and the copper 24 is heated to a temperature 200 to 1200 ° C. higher than its melting point (pure copper is 1083 ° C.) to maintain the temperature. Note that the copper 24 may contain other metal components instead of pure copper. By making the copper 24 a temperature 200 to 1200 ° C. higher than the melting point in vacuum, the vapor of the copper 24 is generated.

  The generated vapor adheres to the polymer film 10 above the container 23. This is vapor deposition. Since vapor is also at a high temperature when adhering to the polymer film 10, the polymer film 10 may be damaged by heat. Therefore, the roller 31 is cooled by the refrigerant r. The polymer film 10 in contact with the roller 31 is cooled from the contact surface with the roller 31, and does not become high temperature even when vapor of the vapor deposition material adheres, and damage due to heat can be prevented.

  In this state, the polymer film 10 is caused to travel from the original fabric 41 toward the product roller 42. During traveling, a nickel or nickel alloy film is formed as the first metal film 12 from the target 22 by sputtering in an atmosphere containing ammonia gas. Thereafter, copper 24 adheres to the polymer film 10 as the second metal film 14 by vapor deposition under the roller 31. The two-layer film 1 in which the first metal film 12 and the second metal film 14 are formed on the polymer film 10 is wound around the product roller 42. The speed at which the polymer film 10 travels is preferably about 1 to 100 m / min, but is not limited to the above range.

  Since the two-layer film 1 can be produced by the above method, a large amount of the two-layer film 1 can be produced industrially. In particular, since the formation of the first metal film 12 by sputtering and the formation of the second metal film 14 by vapor deposition are performed simultaneously, the manufacturing efficiency is increased. In the above description, it has been described that the formation of the first metal film 12 by sputtering and the formation of the second metal film 14 by vapor deposition are performed simultaneously. The formation of the metal film 14 may be performed separately. In this case, in the first run of the polymer film 10, only the first metal film 12 is formed, and the polymer film 10 wound around the product roller 42 is used as the original fabric 41 to run again, Only the second metal film 14 is formed. If comprised in this way, the thickness of the 1st metal film 12 and the thickness of the 2nd metal film 14 can each be adjusted arbitrarily. The formation of the first metal film 12 is not limited to sputtering, and other vacuum film formation methods may be used. The formation of the second metal film 14 is not limited to vapor deposition, and other vacuum film formation methods. Alternatively, other film forming methods may be used.

  Next, with reference to FIG. 1 again, the two-layer films 1-3 which are the 2nd Embodiment of this invention are demonstrated. Here, in the two-layer film 1 which is the second embodiment, only the first metal film 12 is different from the two-layer film described as the first embodiment, and other configurations are the same. Only one metal film 12 will be described, and the other description will be omitted.

  The first metal film 12 is a film formed on the polymer film 10 and contains 50 atomic% to 99 atomic% of nickel and 1 atomic% to 50 atomic% of nitrogen atoms. Here, the remainder other than nickel atoms and nitrogen atoms is generally copper, titanium, or the like, but is not limited thereto. Nickel or nitrogen content (atomic%) is, for example, using a sample in which the first metal film 12 is formed and etching the first metal film 12 side by, for example, sputtering gas particles for 1 minute, After the surface of the first metal film 12 is peeled off, measurement can be performed by component analysis using an X-ray photoelectron spectrometer. When the first metal film 12 contains 50 atom% or more of nickel atoms and 1 atom% or more of nitrogen atoms, the adhesive force between the polymer film 10 and the second metal film 14 becomes strong. However, if a large amount of nitrogen atoms is included so as to exceed 50 atomic%, the adhesive strength decreases. Preferably, the first metal film 12 contains 1 atom% or more and 30 atom% or less, more preferably 1 atom% or more and 20 atom% or less of nitrogen atoms.

  The first metal film 12 is preferably formed by, for example, a vacuum film forming method such as a vacuum deposition method, a sputtering method, or an ion plating method because a uniform and dense film can be obtained. According to these vacuum film forming methods, metal ions ionized in a vacuum are deposited on the polymer film to form a film, so that the film material from which the metal ions originate contains nitrogen as an impurity. Since it is removed when ionized, it is generally not contained in the formed metal film. However, a metal film containing nitrogen atoms is formed by forming a metal film by a vacuum film-forming method in an atmosphere containing any one gas of the group consisting of ammonia, nitric oxide, and nitrogen dioxide. The The first metal film 12 may be formed by a method other than the vacuum film formation method. Note that the film material refers to a material that forms a film in each film forming method, such as a vapor deposition material that is a material of a film to be deposited in a vacuum deposition method and a target that is a film material in a sputtering method. .

  The first metal film 12 functions as an adhesive layer between the polymer film 10 and the second metal film 14. The thickness of the first metal film 12 is preferably 3 nm to 100 nm. The thickness is preferably 5 nm or more, more preferably 10 nm or more, and preferably 30 nm or less. With such a thickness, the adhesion strength between the polymer film 10 and the first metal film 12 and the second metal film 14 is increased. Specifically, the adhesion strength according to the Japan Printed Circuits Industry Association, JPCA standard “copper-clad laminate for flexible printed wiring boards (adhesive and non-adhesive type)” JPCA-BM03-2003 is initially 490 N / m or more. More preferably, it is 590 N / m or more at the initial stage, and it is also preferably 294 N / m or more after dry heating at 120 ° C. for 240 hours. By having this adhesion strength, even if the two-layer film 1 is exposed to heat and exposed to a high temperature, the metal film does not peel off and the two-layer film 1 has a sufficiently large adhesion strength to be used for high-density printed wiring. Become a film.

  Next, with reference to FIG. 1 and FIG. 2, the manufacturing method of the 2 layer film which is 2nd Embodiment is demonstrated. The method for producing the two-layer film according to the second embodiment may be basically the same as the method for producing the two-layer film according to the first embodiment described above. The conditions of the film material for forming are different. In FIG. 2, nickel (hereinafter referred to as a target) 22 as a sputtering target disposed in the traveling path of the polymer film 10 between the raw fabric 41 and the roller 31 has a purity containing 75% by weight or more of nickel. High nickel material. Preferably, when nickel is contained in an amount of 99% by weight or more, the nickel content contained in the film when it is formed is increased, and the force for bonding the polymer film 10 and the second metal film 14 is increased. Furthermore, for example, if nickel is a substantially simple substance containing 99.9% by weight or more, the nickel content contained in the film when it is formed is further increased, and the adhesion force is further increased. is there. A cathode is connected to the target 22, an anode is connected to the polymer film 10 facing the target 22, and a voltage is applied between these electrodes. Near the target 22 and the polymer film 10, a discharge port 44 of a reaction gas pipe 43 for supplying ammonia gas is provided. The reaction gas pipe 43 supplies ammonia gas near the target 22 from an external ammonia gas supply source. When the ammonia gas supplied from the reaction gas pipe 43 is 30% by volume or more, preferably 50% by volume or more, more preferably 60% by volume or more, nickel and nitrogen atoms contained in the first metal film to be formed It is preferable because the content of atoms other than is reduced. By performing sputtering in an atmosphere containing ammonia gas, nitrogen is contained in the nickel film formed on the polymer film 10. When nickel contains nitrogen, the adhesiveness with the polymer film 10 is increased, and a decrease in adhesive strength at high temperatures can be prevented. The gas supplied from the reaction gas pipe 43 is not limited to ammonia gas, and may be nitrogen monoxide or nitrogen dioxide, or a mixed gas thereof or a gas containing these gases, typically argon gas, etc. A mixed gas with an inert gas which is a rare gas may be used. The other steps in the method for manufacturing a two-layer film according to the second embodiment are the same as those described in the method for manufacturing a two-layer film according to the first embodiment, and therefore redundant description is omitted. .

  Then, with reference to the flowchart of FIG. 3, the example of the manufacturing method of a printed circuit board using the 2 layer film which is 1st Embodiment is demonstrated. In FIG. 3, the routes (St16, St27 to 28, and St29) indicated by broken lines are routes that do not necessarily have to be passed (do not be implemented), and do not pass both St16 and St27 to 28. .

  First, ammonia gas is supplied into a vacuumed vacuum chamber (St11), and a nickel film is formed by sputtering while supplying ammonia gas (St12). Further, a copper film is formed on the nickel film in a vacuum chamber to form a two-layer film (St13). As described above, by forming a nickel film while supplying ammonia gas, a nickel film having nitrogen atoms is formed, and by forming a copper film on the nickel film, a polymer film and A two-layer film having a high adhesion strength is formed. The gas to be supplied may be nitrogen monoxide or nitrogen dioxide instead of ammonia, and the method for producing the two-layer film may be other methods as described above.

  For example, in the case of the negative type, a resist is formed by applying a material having a property that is not eluted in the subsequent development process on the copper film of the two-layer film (St21). A mask pattern is exposed on the resist (St22). The resist is cured by being exposed to light and is not dissolved even in a subsequent development step. Therefore, by developing, the uncured resist is eluted, and the resist according to the mask pattern is left on the copper film (St23). If developed, etching is performed (ST24). By etching, the copper film under the portion from which the resist is eluted is eluted. That is, the copper film and the resist remain only in the exposed part. By stripping the resist, the remaining copper film becomes a conductive path, and a substrate on which a printed pattern is formed is manufactured (St25).

  A conductive wire is soldered to the substrate on which the printed pattern is formed (St31), and a predetermined element is mounted to manufacture the printed substrate (St41). According to this printed circuit board manufacturing method, the adhesion strength between the metal layer and the polymer layer is high and the wiring is difficult to peel off, so the conductor width and the space between the conductors can be reduced, and the printed circuit board can be downsized. it can. In addition, you may form the plating film which has copper as a main component by the electrolytic method or the electroless-plating method further on the board | substrate with which the printed pattern was formed (St29). The plating layer mainly composed of copper is formed on the conductive path formed of the copper film, but is not formed on the exposed portion of the polymer film. That is, the plating film is formed on the substrate on which the printed pattern is formed. By forming the conductive path, the conductive path can be thickened. When the conductive path is thick, the conductivity is high, which is preferable.

  After the two-layer film is formed (St13), a copper film may be further stacked by plating or other methods (St16). By forming the copper film in an overlapping manner, the thickness of the copper film becomes thick, that is, the printed conductive path becomes thick and the electric resistance decreases. This is preferable because the conductive path can be thickened without changing the thickness on the printed plane, and the size of the printed board is not increased.

  Alternatively, after the mask pattern is exposed and developed on the two-layer film (St23), a substrate on which a print pattern is formed as follows may be manufactured. First, development is performed to leave only the resist according to the mask pattern, and then copper is plated (St27). Then, since the resist is not plated, copper is plated only on the portion where the copper film is exposed by development. Therefore, the substrate on which the printed pattern is formed is manufactured by removing the resist and the underlying copper film (St28). This method is called a semi-additive method, and a portion to be exposed is a portion on which a conductive path is printed. This is opposite to the method described so far, and is a positive type exposure. Note that exposure in which the unexposed portion is a conductive path is called a negative type. By using this semi-additive method, the thickness of the conductive path (thickness of the copper film) can be easily increased, and moreover, compared to the method of plating the copper film before development, the eluted copper The amount can be reduced, i.e. the consumption of copper can be reduced.

  The method for producing the printed circuit board is not limited to the above, and various methods can be used. The first method includes 60% by weight or more of nickel on a polymer film by a vacuum film-forming method in an atmosphere containing ammonia gas. Then, using the two-layer film on which the second metal film containing copper as a main component is formed, a substrate on which a printed pattern is formed is formed, and the printed circuit board is formed by arranging the elements. By manufacturing, a printed circuit board having high adhesion strength between the metal layer and the polymer layer and preventing the wiring from peeling off is manufactured.

  In order to manufacture a printed circuit board using the two-layer film according to the second embodiment, in the above-described printed circuit board manufacturing method, high purity nickel is used as a film material, etc. May be formed so as to contain 50 atom% or more of nickel atoms and 1 atom% or more of nitrogen atoms. By manufacturing the printed circuit board in this way, a printed circuit board with higher adhesion strength between the metal layer and the polymer layer and less peeling of the wiring is manufactured.

  Hereinafter, the effect of the two-layer film according to the present invention is confirmed by Examples and Comparative Examples. First, Examples 1 to 6 of the two-layer film according to the first embodiment will be described.

  A polyimide film (registered trademark: Kapton EN, manufactured by Toray DuPont) having a thickness of 38 μm, a width of 500 mm, and a length of 200 m is set in a vacuum chamber. The degree of vacuum is 0.04 Pa. Thereafter, sputtering was performed while nickel 100 was used as a target and 100% by volume of ammonia gas was supplied into the vacuum chamber to form a first metal film. The first metal film contained 14 atomic% of nitrogen atoms as detected by the high resolution Rutherford backscattering spectrometry method. Moreover, the thickness was 20 nm. A copper film was formed on the surface of the first metal film by a vacuum deposition method to form a second metal film having a thickness of 200 nm. The prepared film was attached to a batch-type electrolytic plating tank to form a copper plating film (third metal film) having a thickness of 10 μm to produce a two-layer film.

  A polyimide film (registered trademark: Kapton EN, manufactured by Toray DuPont) having a thickness of 38 μm, a width of 500 mm, and a length of 200 m is set in a vacuum chamber. The degree of vacuum is 0.04 Pa. Thereafter, sputtering was performed while using nickel Ni as a target and supplying 100% by volume of nitric oxide gas at 150 ml / min into the vacuum chamber to form a first metal film. The first metal film contained 10 atomic% of nitrogen atoms as detected by the high resolution Rutherford backscattering spectrometry method. Moreover, the thickness was 14 nm. A copper film was formed on the surface of the first metal film by a vacuum deposition method to form a second metal film having a thickness of 200 nm. The created film was attached to a batch-type electrolytic plating tank to form a copper plating film having a thickness of 10 μm to produce a two-layer film.

  A polyimide film (registered trademark: Kapton EN, manufactured by Toray DuPont) having a thickness of 38 μm, a width of 500 mm, and a length of 200 m is set in a vacuum chamber. The degree of vacuum is 0.04 Pa. After that, sputtering is performed while supplying nickel Ni as a target and supplying 150 ml / min of a mixed gas of ammonia gas and nitric oxide gas (ammonia gas 60 vol%, nitric oxide gas 40 vol%) into the vacuum chamber. The metal film was formed. The first metal film contained 7 atomic% of nitrogen atoms as detected by the high resolution Rutherford backscattering spectrometry method. Moreover, the thickness was 14 nm. A copper film was formed on the surface of the first metal film by a vacuum deposition method to form a second metal film having a thickness of 200 nm. The created film was attached to a batch-type electrolytic plating tank to form a copper plating film having a thickness of 10 μm to produce a two-layer film.

  A polyimide film (registered trademark: Kapton EN, manufactured by Toray DuPont) having a thickness of 25 μm, a width of 500 mm, and a length of 200 m is set in the vacuum chamber. The degree of vacuum is 0.04 Pa. Thereafter, an alloy of nickel Ni and copper Cu (Ni: Cu = 80: 20% by weight) is targeted, and a mixed gas of nitrogen dioxide gas and argon gas (nitrogen dioxide gas 50% by volume, argon gas 50% by volume) is 200 ml / min. Was supplied into the vacuum chamber, and sputtering was performed to form a first metal film. The first metal film contained 6 atom% of nitrogen atoms according to detection by the high resolution Rutherford backscattering spectrometry method. Moreover, the thickness was 8 nm. A copper film was formed on the surface of the first metal film by a vacuum deposition method to form a second metal film having a thickness of 200 nm. The created film was attached to a batch-type electrolytic plating tank to form a copper plating film having a thickness of 10 μm to produce a two-layer film.

  A polyimide film (registered trademark: Kapton EN, manufactured by Toray DuPont) having a thickness of 25 μm, a width of 500 mm, and a length of 200 m is set in the vacuum chamber. The degree of vacuum is 0.04 Pa. Thereafter, sputtering is performed while an alloy of nickel Ni and chromium Cr (Ni: Cr = 80: 20 wt%) is used as a target and 100 volume% ammonia gas is supplied into the vacuum chamber, and the first metal film is sputtered. Was formed. The first metal film contained 11 atomic% of nitrogen atoms as detected by the high resolution Rutherford backscattering spectrometry method. Moreover, the thickness was 10 nm. A copper film was formed on the surface of the first metal film by a vacuum deposition method to form a second metal film having a thickness of 200 nm. The created film was attached to a batch-type electrolytic plating tank to form a copper plating film having a thickness of 10 μm to produce a two-layer film.

  A polyimide film (registered trademark: Kapton EN, manufactured by Toray DuPont) having a thickness of 25 μm, a width of 500 mm, and a length of 200 m is set in the vacuum chamber. The degree of vacuum is 0.04 Pa. After that, sputtering is performed while nickel 100 is used as a target and a mixed gas of ammonia gas and argon gas (ammonia gas 70 vol%, argon gas 30 vol%) 100 ml / min is supplied into the vacuum chamber. A film was formed. The first metal film contained 10 atomic% of nitrogen atoms as detected by the high resolution Rutherford backscattering spectrometry method. Moreover, the thickness was 10 nm. A copper film was formed on the surface of the first metal film by a vacuum deposition method to form a second metal film having a thickness of 200 nm. The created film was attached to a batch-type electrolytic plating tank to form a copper plating film having a thickness of 10 μm to produce a two-layer film.

In order to compare with Examples 1-6, the two-layer film was manufactured by the following comparative examples 1 and 2 which changed the gas to supply.
[Comparative Example 1]
In the same manner as in Example 1, the gas to be supplied was changed to 100% by volume of argon gas to produce a two-layer film. The first metal film did not contain nitrogen atoms, as detected by high resolution Rutherford backscattering spectrometry. The thickness of the first metal film was 20 nm.
[Comparative Example 2]
In the same manner as in Comparative Example 1, the target was changed to an alloy of nickel Ni and copper Cu (Ni: Cu = 80: 20 wt%) to produce a two-layer film. The first metal film did not contain nitrogen atoms, as detected by high resolution Rutherford backscattering spectrometry. The thickness of the first metal film was 10 nm.

  About the two-layer film manufactured by the method of said Examples 1-6 and Comparative Examples 1 and 2, the adhesive strength after manufacture (initial stage) and the adhesive strength after heat resistance were measured. The adhesion strength after heat resistance was determined by measuring the adhesion strength of the two-layer film after being held at 120 ° C. for 240 hours using a gear open. The adhesion strength was measured in accordance with the Japan Printed Circuits Industry Association, JPCA standard “copper-clad laminate for flexible printed wiring boards (adhesive and non-adhesive type)” JPCA-BM03-2003.

  In FIG. 4, the measurement result of the adhesive strength of the bilayer film of Examples 1-6 and Comparative Examples 1 and 2 is shown collectively. As is clear from FIG. 4, in each of the two-layer films of Examples 1 to 6, a high initial adhesion strength of 500 N / m or more was shown in each case, and the adhesion strength after heat resistance was 300 N / m or more. The result of maintaining the adhesion strength was shown. On the other hand, in the comparative example, although the initial strength is 350 N / m or more, the adhesion strength after heat resistance is as low as 150 N / m or less. Therefore, the first metal film formed by the vacuum film-forming method in an atmosphere containing any one gas of the group consisting of ammonia, nitric oxide, and nitrogen dioxide using a metal having a high nickel content It was shown that the two-layer film provided with a high initial adhesion strength and adhesion strength after heat resistance. In particular, according to sputtering in an atmosphere containing any one gas of the group consisting of ammonia, nitrogen monoxide, and nitrogen dioxide using a target material containing nickel Ni alone or 80% by weight of nickel Ni, High adhesion strengths of initial adhesion strength of 540 N / m or more and adhesion strength after heat resistance of 310 N / m were obtained. Note that these first metal films contained 6 to 14 atomic% of nitrogen atoms as measured by the high resolution Rutherford backscattering spectrometry method.

It is sectional drawing of the two-layer film which is embodiment of this invention. (A) is a two-layer film in which a first metal film and a second metal film are formed on one side of a polymer film. (B) is a two-layer film in which a first metal film and a second metal film are formed on both surfaces of a polymer film. (C) is a two-layer film in which a first metal film and a second metal film are formed on one surface of a polymer film, and a third metal film is further formed. It is a schematic cross section of the manufacturing apparatus of a two-layer film. It is a flowchart explaining the example of the manufacturing method of the printed circuit board using a two-layer film. It is the figure which put together the measurement result of the adhesive strength in the two-layer film of the Example by the 1st Embodiment of this invention, and a comparative example.

Explanation of symbols

1-3 Bilayer film 10 Polymer film 12 1st metal film 14 2nd metal film 16 3rd metal film 22 Target 23 (deposition material) container 24 Deposition material 31 Roller 32, 32 'Guide roller 33 Vacuum Tank 34 Intake pipe 35 Vacuum pumps 36, 37 Refrigerant pipe 41 Raw fabric 42 Product roll 43 Reaction gas pipe 44 Discharge port r Refrigerant

Claims (10)

A polymer film;
Nickel formed on the polymer film by a vacuum deposition method, an ion plating method, or a sputtering method in an atmosphere containing any one gas of the group consisting of ammonia, nitric oxide, and nitrogen dioxide. A first metal film comprising 60 wt% or more and 100 wt% or less;
A second metal film mainly composed of copper formed on the first metal film;
Two-layer film. A polymer film;
Nickel atoms formed on the polymer film by a vacuum deposition method, an ion plating method, or a sputtering method in an atmosphere containing any one gas of the group consisting of ammonia, nitric oxide, and nitrogen dioxide A first metal film containing 50 atom% to 99 atom% and nitrogen atom 1 atom% to 50 atom%;
A second metal film mainly composed of copper formed on the first metal film;
Two-layer film. The adhesion strength between the polymer film and the first metal film is initially 490 N / m or more, and the adhesion strength after drying at 120 ° C. for 240 hours is 294 N / m or more;
The two-layer film according to claim 1 or 2. The polymer film is formed of a polymer containing nitrogen atoms;
The two-layer film according to any one of claims 1 to 3. The polymer containing nitrogen atoms includes any one of the group consisting of polyimide, polyetherimide, polyamideimide and aramid;
The two-layer film according to claim 4. The thickness of the first metal film is 3 nm or more and 100 nm or less;
The thickness of the second metal film is 20 nm or more and 5000 nm or less;
The two-layer film according to any one of claims 1 to 5. On the second metal film, a third metal film mainly composed of copper was formed by an electrodeposition method or an electroless plating method;
The two-layer film according to any one of claims 1 to 6. 60% by weight of nickel is deposited on the polymer film by a vacuum deposition method, an ion plating method or a sputtering method in an atmosphere containing any one gas of the group consisting of ammonia, nitric oxide and nitrogen dioxide. Forming a first metal film containing 100% by weight or less;
Forming a second metal film mainly composed of copper on the first metal film;
A method for producing a two-layer film. 50 atoms of nickel atoms are formed on the polymer film by vacuum deposition, ion plating, or sputtering in an atmosphere containing any one gas selected from the group consisting of ammonia, nitric oxide, and nitrogen dioxide. Forming a first metal film containing no less than 99% and no more than 99% and nitrogen atoms of no less than 1% and no more than 50%;
Forming a second metal film mainly composed of copper on the first metal film;
A method for producing a two-layer film. A step of producing a two-layer film by the method for producing a two-layer film according to claim 8 or 9;
Forming a print pattern on the two-layer film produced by the two-layer film production method;
Arranging a device on the two-layer film on which the print pattern is formed;
A method for manufacturing a printed circuit board.

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