JP2008162245A - Plating-method two-layer copper polyimide laminated film, and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plating-method two-layer copper polyimide laminated film excellent in adhesion durability in the interface between a polyimide film and a conductive metal layer on the polyimide film, namely a normal state adhesion force, a heat-resistant adhesion force and a high-temperature high-humidity adhesion force in the plating-method two-layer copper polyimide laminated film which uses no adhesive, and to provide a method for forming the film. <P>SOLUTION: The plating-method two-layer copper polyimide laminated film which keeps a metal vapor deposition layer overlying one side or both sides of a polyimide film with a conductive metal layer which is composed of copper overlaying the metal vapor deposition layer to unify them is characterized in that a surface modification depth index after eliminating the conductive metal layer by etching is 25 or smaller and a surface modification strength index is 1.1 or more. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plating method two-layer copper-polyimide laminated film suitably used for flexible printed wiring board applications and a method for producing the same.

  As electronic devices become smaller, lighter, more functional, multifunctional, and more densely packed, printed wiring boards used in these electronic devices are made narrower, multi-layered, and flexible between conductors and conductors. As the substrate becomes thinner, the density is rapidly increasing, and the substrate has been developed into a flexible printed circuit (hereinafter sometimes referred to as FPC) substrate.

  Conventionally, a flexible printed wiring board having a three-layer structure in which a copper foil as a conductor layer is bonded to a polyimide film via an adhesive layer is known. The three-layer structure type flexible printed wiring board has a problem that the heat resistance of the adhesive used is inferior to that of the polyimide film, so that the dimensional accuracy after processing decreases, and the thickness of the copper foil used is usually Since the thickness is 10 μm or more, there is a disadvantage that patterning for high-density wiring with a narrow pitch is difficult. Furthermore, with this three-layer structure type flexible printed wiring board, the adhesive is melted or thermally decomposed by the IC heated to a high temperature during IC mounting, so the IC bumps and the leads on the FPC are accurate. Cannot be connected. Therefore, when mounting an IC, it is common to make a hole by punching the IC mounting position by a method such as punching so that no adhesive is interposed under the IC chip.

  On the other hand, two layers in which a metal layer as a conductor layer is formed on a polyimide film by a wet plating method or a dry plating method (for example, a vacuum deposition method, a sputtering method, an ion plating method, etc.) without using an adhesive. Structural type flexible printed wiring boards are known (see Patent Documents 1, 2, and 3). These two-layer type flexible printed wiring boards that do not use adhesives do not have adhesives, so there is no need to make holes in the film surface as described above when mounting ICs, and directly on the polyimide film. An IC can be mounted. However, the flexible printed wiring board of this plating method two-layer structure type can make the conductor layer thinner than 10 μm, so that the flexibility of the FPC is very good and high-density wiring is possible. There was a drawback that the adhesion between the conductor layer and the polyimide film was lower than that of a three-layer type flexible printed wiring board using an adhesive. Since the apparent adhesion force is proportional to the thickness of the conductor layer, if the conductor layer is as thick as 18 μm or 35 μm, the adhesion force is not so much a problem, but the conductor layer thickness is reduced as less than 10 μm. The value of the adhesion force becomes smaller, and a higher level of adhesion force is required.

In addition, such a plating method two-layer type copper-clad laminate is being used for film capacitors and the like, and high adhesion is also required in these applications. In a two-layer plating base material, it is generally known that a plastic film, which is a base film before plating, is subjected to vacuum plasma treatment, ion irradiation, corona discharge treatment or atmospheric pressure plasma treatment as pretreatment ( (See Patent Document 4). However, these techniques alone have not been sufficient to obtain adhesion to a fine pitch such that the circuit pitch in recent years is less than 40 μm. In addition, when a thermal load is applied to the circuit, when the circuit is exposed to a high-temperature and high-humidity atmosphere, the surface treatment as described above may return depending on conditions and reduce the adhesion. It was.
Japanese Patent Laid-Open No. 2002-20898 Japanese Patent Laid-Open No. 2003-321796 Japanese Patent Laid-Open No. 9-235697 JP-A-1-321687

  Accordingly, an object of the present invention is to provide adhesion durability at the interface between a polyimide film and a conductor layer on the polyimide film, that is, a conductive metal layer, in a plating method two-layer copper polyimide laminated film that does not use an adhesive. An object of the present invention is to provide a plating method two-layer copper polyimide laminated film excellent in heat-resistant adhesion and high-temperature and high-humidity adhesion and a method for producing the same.

  The present invention is intended to solve the above-mentioned problems, and the plating method two-layer copper polyimide laminated film of the present invention is provided with a metal vapor deposition layer on one side or both sides of the polyimide film, and copper is deposited on the metal vapor deposition layer. A plating method two-layer copper polyimide laminated film obtained by laminating and integrating a conductive metal layer comprising a surface modification depth index of 25 or less after removal of the conductive metal layer by etching, and a surface It is a plating method two-layer copper polyimide laminated film characterized by having a modified strength index of 1.1 or more.

  According to a preferred embodiment of the plating method two-layer copper polyimide laminated film of the present invention, the polyimide constituting the polyimide film uses pyromellitic dianhydride or / and biphthalic dianhydride as an acid anhydride component, This is a polyimide polymerized by combining oxydianiline and / or paradianiline as a diamine component and combining them.

  According to the preferable aspect of the plating method 2 layer copper polyimide laminated film of this invention, the thickness of the said conductive metal layer is 1.0 micrometer or more and less than 10 micrometers.

  According to a preferred embodiment of the plating method two-layer copper polyimide laminated film of the present invention, the surface modification depth index of the polyimide film is 20 or less.

  According to a preferred aspect of the plating method two-layer copper polyimide laminated film of the present invention, the metal vapor-deposited layer includes a nichrome layer having a thickness of 1 nm to 50 nm in which the ratio of nickel to chromium is 97: 3 to 70:30. It is composed of.

  The vapor deposition for forming the metal vapor deposition layer here means any one of a vacuum vapor deposition method, a sputtering method, and an ion plating method, but the sputtering method enhances the adhesion between the metal vapor deposition layer and the polyimide. Most preferred above.

  The plating method 2 layer copper polyimide laminated film of this invention is suitable for manufacture of the board | substrate for flexible printed wiring.

  Moreover, the manufacturing method of the plating method 2 layer copper polyimide laminated film of this invention is the surface modification depth index of 20 or less, and the surface modification strength index is 1.1 or more on one side or both sides of the polyimide film. A method for producing a two-layer copper polyimide laminated film by plating, characterized in that a metal vapor deposition layer is provided, and a conductive metal layer made of copper is laminated and integrated on the metal vapor deposition layer.

  According to the preferable aspect of the manufacturing method of the plating method 2 layer copper polyimide laminated film of this invention, as said metal vapor deposition layer, the ratio of Ni and Cr consists of 97: 3-70: 30, and thickness is 3 nm or more and 20 nm The metal vapor deposition layer containing the following nichrome layers is provided.

  By using the manufacturing method of the laminated board of this invention, the plating method 2 layer copper polyimide laminated film excellent in adhesiveness is obtained. Moreover, conventionally, for example, a copper foil of less than 12 μm was not produced due to the limit of the thickness of the copper foil, but when a thin copper layer of 0.5 to 10 μm can be formed, it can be used as an FPC substrate. Pattern accuracy is improved, and wiring with higher density and higher accuracy becomes possible. In addition, there are few breaks and pinholes that have occurred during the lamination of the copper foil, and it is possible to obtain a product that is economical and has high quality.

  The plating method two-layer copper polyimide laminated film of the present invention is, for example, as an FPC board or a COF board, or as a film for a film capacitor or other electronic component material, such as an electronic computer, a terminal device, a telephone, a communication device, a measurement control device, It can be used in all electronics fields such as cameras, watches, automobiles, distribution equipment, home appliances, aircraft instruments and medical equipment. Moreover, application to a connector, a flat electrode, etc. is also possible.

  The plating method two-layer copper polyimide laminated film of the present invention is a two-layer plating method in which a metal vapor deposition layer is provided on one or both sides of a polyimide film, and a conductive metal layer made of copper is laminated on the metal vapor deposition layer. A copper polyimide laminated film having a surface modification depth index of 25 or less and a surface modification strength index of 1.1 or more after the conductive metal layer is removed by etching. It is a plating method 2 layer copper polyimide laminated film.

  In the plating method two-layer copper polyimide laminated film of the present invention, even if the surface modification depth index exceeds 25, the normal adhesion can be expected to have a certain level, but the adhesion when exposed to a heat load is expected. There is a high possibility that the decline of The surface modification depth index is preferably 20 or less, more preferably 15 or less. This surface modification depth index is preferably as close to zero as possible.

  In the present invention, the surface modification depth index is defined as follows. In the X-ray photoelectron analysis method on the film surface, when the photoelectron escape angle (angle of the detector with respect to the sample surface) is changed, photoelectrons at deeper positions from the film surface are detected as the angle increases. Therefore, when only the very surface vicinity of the film is modified by any method, the state of the elemental composition by the modification is detected only when the angle is small, and when the angle becomes large, the original polymer that has not been modified The elemental composition is almost the same as the composition. The angle showing the element composition almost the same as this polymer composition is defined as the surface modification depth index. In the present invention, paying attention to oxygen atoms and nitrogen atoms constituting the polyimide film, the atomic ratio of carbon to the angle between them (that is, to the depth) is the same as the original polymer composition not modified (above) Of the angles that become the ratio of the number of atoms when the photoelectron escape angle is 45 degrees, the larger value is defined as the surface modification depth index.

  Moreover, in the plating method two-layer copper polyimide laminated film of the present invention, the above-mentioned surface modification strength index can be expected to have a certain level of normal adhesion even if it is less than 1.1, but when exposed to a heat load. There is a high possibility that the decrease in adhesion will be large. The preferred surface modification strength index is 1.1 to 5.0, more preferably 1.1 to 2.0, and even more preferably 1.5 to 1.8.

  In the present invention, the surface modification strength index is defined as follows. The ratio between the surface layer (angle 5 °) and the deep layer (angle 45 °) of the atomic ratio of the element that is changed by the modification to the photoemission angle is defined as the strength index.

  The reason why the adhesion strength is improved when the surface modification strength index is in the above range is that the damage due to the surface modification remains on the surface layer from the film surface. This is thought to be because it can be prevented from spreading.

  Next, the manufacturing method of the plating method 2 layer copper polyimide laminated film in this invention is explained in full detail.

  When the base material polyimide film used in the present invention is exemplified, pyromellitic acid (PMDA) dianhydride or / and biphthalic acid (BPDA) dianhydride is used as the acid anhydride component, and oxydianiline ( ODA) and / or paradianiline (PDA), and those obtained by combining these to form a film of polyimide. “Kapton EN” (registered trademark) manufactured by Toray DuPont falls under this category. Moreover, you may contain these copolymers and another organic polymer. Known additives such as lubricants and plasticizers may be added to these polyimides.

  As for the thickness of the polyimide film which is a base material, the thing of about 6-125 micrometers is used abundantly, and the thickness of 12-50 micrometers is suitable.

  In the present invention, it is important to perform a pretreatment (such as a hydrophilization treatment) on the surface of the polyimide film before metal deposition on the polyimide film. This pre-treatment method is one factor that keeps the surface modification depth index and the surface modification strength index in the present invention within the above ranges. In addition, the method of drying the polyimide film in a vacuum dryer with a gas pressure of 10 Pa or less for 2 days or more, or the method of drying with an infrared heater while winding the polyimide film, the surface modification depth index of the present invention and the surface The modified strength index is an effective means for realizing the surface modified depth index and the surface modified strength index of the present invention within the above range.

Examples of the pretreatment method include corona discharge treatment, atmospheric pressure plasma treatment, vacuum plasma treatment, ion gun treatment, and plasma gun treatment, but vacuum plasma treatment is most preferred. In this vacuum plasma treatment, nitrogen, argon, or a mixed gas thereof is preferably used as the plasma gas. In the plasma treatment, it is particularly preferable to pay attention to the following points.
-The discharge output of the plasma treatment is suppressed to 1.5 KW / m ² or less. The preferred discharge output is
0.5 to 1.5 KW / m ² .
-Discharge the plasma treatment atmosphere at a pressure of 5 Pa or less. A preferable pressure is 0.5 to 5 Pa.
・ During the plasma treatment, the moisture discharged from the polyimide film is removed using a cryocoil or the like.
・ Metal vapor deposition is performed within 15 minutes after plasma treatment.
・ To avoid direct irradiation of the polyimide film of gas molecules (or atoms), ions, and radicals present in the plasma processing atmosphere, trap the ions with a grid electrode installed in the processing equipment, As much as possible, the treatment is performed mainly with radicals or excited neutral particles.
-In addition, it is desirable to perform the vapor deposition treatment without breaking the vacuum after the pretreatment.

  Following the pretreatment step, a metal vapor deposition layer is formed on one or both sides of the polyimide film by vacuum vapor deposition or sputtering. As the metal constituting the metal vapor deposition layer and the conductive metal layer provided thereon, copper having low electric resistance, excellent flexibility and low cost is suitable.

  The metal vapor deposition layer provided on a polyimide film can be usually made into a two-layer structure. In this two-layer structure, the reason why the first layer is provided is a role as a crystal nucleus for forming the second layer and a role as a barrier for preventing the copper of the second layer from diffusing into the polyimide. Examples of the metal constituting the metal vapor-deposited first layer in direct contact with the polyimide film include titanium, molybdenum, nickel, chromium, cobalt, etc., preferably nickel and chromium as main components, and nickel in the nichrome layer. The ratio (weight ratio) of chromium is preferably 98: 2 to 50:50, and more preferably 97: 3 to 70:30. If the ratio of chromium is less than 2%, the magnetism of the alloy becomes strong, so that it is difficult to discharge for sputtering. Further, if the chromium ratio is higher than 50%, the metal deposition first layer may remain during etching for forming a circuit pattern, and the insulation reliability of the circuit may be lowered.

  The thickness of this metal vapor deposition 1st layer becomes like this. Preferably it is 1-50 nm, More preferably, it is 2-40 nm.

  The purpose of providing this metal deposition first layer is to prevent the metal (copper) of the conductive metal layer to be plated and laminated later from diffusing into the polyimide film. On the metal deposition first layer, a second metal deposition second layer serving as a conductive layer for electrodepositing a plating layer (conductive metal layer) is provided. It is preferable that this metal vapor deposition 2nd layer consists of copper, The thickness becomes like this. Preferably it is 10-300 nm, More preferably, it is 30-200 nm, More preferably, it is 40-150 nm. When the thickness of the metal vapor deposition second layer is less than 10 nm, the metal vapor deposition second layer is easily eluted in the metal plating step, and when the thickness of the metal vapor deposition second layer is thicker than 300 nm, The film of the metal deposition second layer is likely to peel off after the metal plating step.

  The total thickness of the metal deposition layer including the first layer and the second layer is preferably 31 nm or more and 250 nm or less.

  The resistance value of the surface of the metal vapor deposition layer is preferably 1.0 Ω / cm or less (resistance value measured at a distance of 1 cm between terminals is 1.0 Ω or less), and is preferably as small as possible.

Next, a thicker conductive metal layer made of copper is formed on the metal vapor deposition layer by electrolytic copper plating. Prior to this electrolytic copper plating process, a thick metal layer may be formed by electroless copper plating to fill the pinholes in the sputtered film or by metal vapor deposition again. The electrolytic copper plating step includes degreasing and acid activation treatment, metal strike, and copper plating steps for improving adhesion. When the electrolytic copper plating process is started immediately after depositing the thin metal deposition layer, the degreasing and acid activation treatment process and the metal strike process may be omitted. The current density supplied to the conductive metal layer made of copper is preferably 0.2 to 10 A / dm ² , more preferably 0.5 to 5 A / dm ² . Also, electroless copper plating can be applied instead of electrolytic copper plating.

  The thickness of the copper conductive metal layer to be formed is preferably 0.5 to 35 μm, and is preferably 1.0 μm or more and less than 10 μm when a fine pitch FPC is formed. If the thickness of the conductive metal layer is less than 0.5 μm, the reliability of the plating layer is not necessarily sufficient. In addition, if the thickness of the conductive metal layer exceeds 35 μm, it takes time to form the conductive metal layer of film copper, resulting in inferior economy, and the edge etching of the circuit pattern is likely to proceed during the etching process. It is not preferable in terms of quality, such as there is a risk of disconnection. When the plating method two-layer copper polyimide laminated film of the present invention is used as a high-density printed circuit board with a circuit pitch of 60 μm or less, or when used as a film capacitor, the current density of the target circuit However, from the viewpoint of workability and quality, the thickness of the conductive metal layer is more preferably 1.0 or more and less than 10 μm.

  The plating conditions vary depending on the composition of the plating bath, the current density, the bath temperature, the stirring conditions, and the like, and are not particularly limited. Preferable plating baths used in the present invention include, for example, a copper sulfate bath, a copper pyrophosphate bath, a copper cyanide bath, a copper-tin-zinc alloy plating bath, a tin-nickel-copper alloy plating bath, and the like. When used as a printed wiring board, noble metal plating such as tin plating, gold cyanide plating, silver cyanide plating, rhodium plating and palladium plating may be supplementarily formed on the terminal portion after etching the circuit pattern.

  FIG. 4 is a side view for illustrating an example of a sputtering apparatus capable of sequentially performing plasma processing and sputtering used in the present invention.

  In FIG. 4, a plastic film 4 is mounted on the unwinding machine 5 in the unwinding chamber 1 and supported by a guide roll 11 installed in the apparatus, while being transported along the transport path, and passed through the film forming chamber 2 and the winding chamber. Winding is performed by a winder 9 installed in No. 3. Each chamber is brought to a predetermined degree of vacuum with a vacuum pump. In order to maintain the difference in the degree of vacuum between the chambers, a slit roll 10 and, if necessary, a buffer chamber may be provided. In the film forming chamber, sputtering is performed with the film held on the cooling roll 7, and a plurality of sputtering cathodes 8 (four in FIG. 4) around the cooling roll are adhered to a desired thickness. In the present invention, it is preferable to perform a pretreatment before the sputtering to make the surface of the plastic film 4 hydrophilic, but this pretreatment is preferably performed between unwinding and sputtering in the sputtering apparatus. In the example of FIG. 4, the pretreatment device 6 is installed in the unwinding chamber 1, but it may be provided in the film forming chamber 2 or the buffer chamber. Examples of the pretreatment method include vacuum plasma treatment, ion irradiation, corona discharge treatment, and atmospheric pressure plasma treatment, but in the present invention, vacuum plasma treatment is most preferred. In addition, condensable substances such as moisture may come out from the polyimide film by this pretreatment, and a refrigerant cooled to below −100 ° C. by a refrigerator is passed through the chamber where the pretreatment machine is installed. It is desirable to install a pipe (cryocoil) or the like to remove these condensable substances out of the system.

  The plating method two-layer copper polyimide laminated film of the present invention is suitably used for flexible printed wiring board applications, particularly as an FPC board or COF board, or as a film for film capacitors or other materials for electronic components, electronic computers, terminals. Can be used in all fields of electronics such as equipment, telephones, communication equipment, measurement and control equipment, cameras, watches, automobiles, distribution equipment, home appliances, aircraft instruments and medical equipment, and to connectors and flat electrodes Is also possible.

  Hereinafter, the present invention will be described in detail by way of examples. Each characteristic value in the examples was measured according to the following measurement method.

1. Peel strength: Evaluation was made according to JIS C6471 (180 degree peel) (2005).
(1) Normal adhesion strength: The above evaluation was carried out at a temperature of 100 ° C. for 15 minutes after pattern formation and measured under normal temperature and normal humidity.
(2) Heat-resistant peel adhesion: The above evaluation was carried out at a temperature of 150 ° C. for 10 days after pattern formation, taken out, and then measured under normal temperature and humidity.
(3) High-temperature, high-humidity peel adhesion: The above evaluation was carried out at room temperature and humidity after leaving the pattern at 121 ° C., 100% RH, 2 atm for 4 days.

2. Surface Modification Depth Index: For the plating method two-layer copper polyimide laminated film manufactured by the above-described manufacturing method, the surface of the polyimide film after removing all the metal layers by etching using a copper chloride or iron chloride solution, or Elemental analysis was performed by X-ray photoelectron spectroscopic analysis on the polyimide film surface before metal vapor deposition and the film surface after pretreatment, and the atomic ratio (O / C, N / C) of each component element was obtained. The analysis conditions are as follows.
・ X-ray source: Single crystal spectroscopic AlKα ray ・ X-ray spot: 1000 × 1700μ ellipse ・ Photoemission angle: Measured at each level of θ = 5 °, 10 °, 15 °, 35 °, 45 ° As the escape angle is smaller, the state of the layer closer to the film sample surface is reflected. FIG. 1 is a graph in which the distribution of the atomic ratio with respect to the angle is plotted focusing on nitrogen in Example 1, and the sample at a photoelectron escape angle of 5 ° to 45 ° is shown for a sample not pretreated with polyimide film. When the value of the atomic ratio to be plotted is plotted against the photoemission angle (FIG. 1: ratio of nitrogen to carbon in this case), a substantially horizontal straight line is obtained.

  On the other hand, for example, in the case where the polyimide film was subjected to surface modification in Example 1 described later, the closer to the surface layer, that is, the smaller the photoemission angle (for the effect of surface modification), the atomic ratio is As the angle increases, the value of the atomic ratio of interest decreases and becomes equal to the value of the straight line 1 as the angle increases. Conceptually, the depth at which the effect of this surface modification becomes as low as that of the untreated portion is the surface modification depth. Obtain an approximate straight line by the least square method for the measurement points from 5 ° to 15 °, and the angle of the point that intersects the horizontal straight line (straight line 1 in FIG. 1) at the escape angle of 45 °. The value of 18 is 18 °.

  FIG. 2 shows that the surface modification depth index is about 17 ° in the same manner as in Example 1 with 18 ° having a large value in this case.

  The escape depth at a photoelectron escape angle of 45 ° is several nm (less than 10 nm), and a surface modification depth index of 25 or less is considered to be a very surface layer of less than 3 nm.

3. Surface modification strength index:
In the above plot of the atomic ratio with respect to the photoemission angle, the value of the atomic ratio at an angle of 5 ° and the atomic ratio at the angle of 45 ° (target element / carbon C) is defined as the surface modification strength index. The surface modification depth index and the surface modification strength index were measured in the same manner for the film before sputtering. For the measurement, Quantum 2000 manufactured by PHI was used.

(Example 1)
A 25 μm thick polyimide film “Kapton EN” (registered trademark, manufactured by Toray DuPont Co., Ltd.) 3000 m roll is dried in a vacuum dryer for 2 days, and then the plasma processing device and the sputtering processing device are integrated into the plasma processing and sputtering. Was performed (see FIG. 4), and plasma treatment was performed on one side of the polyimide film. The plasma treatment was performed at an RF power (13.56 MHz) of 0.9 kW / m ² / min in a vacuum chamber having a vacuum degree of 5 mPa or less, introducing nitrogen gas to 2.0 Pa. The pretreatment was performed using a cryocoil while removing moisture released from the inside of the polyimide film during the treatment. The surface modification depth index and the surface modification strength index at this time were values shown in Table 1 (before metal deposition). Next, using a target of 95% chromium and 95% nickel, sputter deposition was performed on the plasma-treated surface of the polyimide film to form a nickel chromium deposition layer having a thickness of 30 n Å, which was the metal deposition first layer. Further, 99.99% pure copper was sputter-deposited on the metal deposition first layer to form a copper deposition layer having a thickness of 900 angstroms. A metal vapor deposition layer composed of a metal vapor deposition first layer and a metal vapor deposition second layer was formed on the film. Thereafter, electrolytic copper plating with a thickness of 8 μm was performed, a conductive metal layer was formed on the metal vapor-deposited layer, and a plating method two-layer copper polyimide laminated film was prepared. The surface modification depth index and the surface modification strength index after removing the copper layer of the obtained plating method two-layer copper polyimide laminated film by etching were the values shown in Table 1 (after copper etching). Table 1 also shows values of adhesion strength under normal conditions, heat resistance, and high temperature and high humidity.

(Example 2)
In Example 1, a plating method two-layer copper polyimide laminated film was prepared in the same manner as in Example 1 except that the thickness of the polyimide film was 38 μm.

(Example 3)
In the pretreatment in Example 2, the wire mesh connected to the ground was installed as a grid in front of the cathode of the pretreatment device, and the pretreatment was performed (the ion current was trapped by the wire mesh, and the polyimide film was free of radicals and excitation. In the same manner as in Example 2 except that the probability of collision of neutral atoms (or molecules) is increased), a plating method two-layer copper polyimide laminated film was prepared.

Example 4
In Example 3, except that the thickness of the nichrome vapor-deposited layer was changed to 150 Å, a plating method two-layer copper polyimide laminated film was prepared in the same manner as in Example 3.

(Example 5)
In Example 4, a plating method two-layer copper polyimide laminated film was prepared in the same manner as Example 4 except that the gas used for the pretreatment was changed from nitrogen to argon.

(Example 6)
In Example 4, a plating method two-layer copper polyimide laminated film was prepared in the same manner as in Example 4 except that the polyimide film was not pretreated.

(Comparative Example 1)
In Example 1, except that the strength of the pretreatment was increased (gas 4.0 Pa, output 4 kW / m ² / min), a plating method two-layer copper polyimide laminated film was prepared in the same manner as in Example 1.

(Comparative Example 2)
In Example 2, except that the strength of the pretreatment was increased (gas 4.0 Pa, output 4 kW / m ² / min), a plating method two-layer copper polyimide laminated film was prepared in the same manner as in Example 1.

  The results of measuring the characteristics of these samples (plating method two-layer copper polyimide laminated film) are summarized in Table 1 below.

  From Table 1 above, it can be seen that the plating method two-layer copper polyimide laminate film of the present invention is superior to the plating method two-layer copper polyimide laminate film of the comparative example in all of the normal state, heat resistance and high temperature and high humidity adhesion. .

  The plating method two-layer copper polyimide laminated film of the present invention is, for example, as an FPC board or a COF board, or as a film for a film capacitor or other electronic component material, such as an electronic computer, a terminal device, a telephone, a communication device, a measurement control device, It can be used in all fields of electronics such as cameras, watches, automobiles, distribution equipment, home appliances, aircraft instruments and medical equipment, and can also be applied to connectors and flat electrodes.

FIG. 1 is a graph showing how to obtain the surface modification depth index and the surface modification strength index, and the values of the surface modification depth index and the surface modification strength index in Example 1. FIG. 2 is a graph showing how to obtain the surface modification depth index and the surface modification strength index, and the values of the surface modification depth index and the surface modification strength index in Example 1. FIG. 3 is a graph showing a surface modification depth index and a surface modification strength index in Example 5. FIG. 4 is a side view for illustrating an example of a sputtering apparatus capable of sequentially performing plasma processing and sputtering used in the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Unwinding chamber 2 Film-forming chamber 3 Winding chamber 4 Plastic film 5 Unwinding machine 6 Pretreatment apparatus 7 Cooling roll 8 Sputtering cathode 9 Winding machine 10 Slit roll 11 Guide roll

Claims (7)

  A plating method two-layer copper polyimide laminated film in which a metal vapor deposition layer is provided on one or both sides of a polyimide film, and a conductive metal layer made of copper is laminated on the metal vapor deposition layer and integrated. A plating method two-layer copper-polyimide laminated film, wherein the surface modification depth index after removing the film by etching is 25 or less and the surface modification strength index is 1.1 or more.   Polyimide constituting the polyimide film was polymerized by combining pyromellitic dianhydride and / or biphthalic dianhydride as the acid anhydride component and oxydianiline or / and paradianiline as the diamine component, and combining them. The plating method two-layer copper polyimide laminated film according to claim 1, which is polyimide.   The plating method two-layer copper polyimide laminated film according to claim 1 or 2, wherein the thickness of the conductive metal layer is 1.0 µm or more and less than 10 µm.   The surface modification depth index of a polyimide film is 20 or less, The plating method 2 layer copper polyimide laminated film in any one of Claims 1-3 characterized by the above-mentioned.   Any one of 1-4 characterized in that the metal vapor deposition layer is composed of a layer containing a nichrome layer having a thickness (weight ratio) of 97: 3 to 70:30 of nickel and chromium having a thickness of 1 nm to 50 nm. The plating method 2 layer copper polyimide laminated film of description.   A metal vapor-deposited layer is provided on one or both sides of a polyimide film having a surface-modified depth index of 20 or less and a surface-modified strength index of 1.1 or greater, and the conductivity is made of copper on the metal vapor-deposited layer. A method for producing a two-layer copper-polyimide film by plating, characterized by laminating and integrating metal layers.   The board | substrate for flexible printed wiring using the plating method 2 layer copper polyimide laminated film in any one of Claims 1-5.

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