JP2009078491A - Method for manufacturing laminate film with metal layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing remarkably efficiently a laminate film with a metal layer that has good appearance. <P>SOLUTION: Provided is a method for manufacturing a laminate film with a plurality of metal layers, which comprises at least, in the following order, (1) the process of forming a laminate that has heat-resistant resin layers on both surfaces of a release layer-provided metal foil that has metal layers on both surfaces of it and (2) the process of separating the release layer-provided metal foil at the release layer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a laminated film with a metal layer. More specifically, the present invention relates to a method for producing a laminated film with a metal layer, which has a heat-resistant resin layer on the metal layer and is suitably used for a flexible circuit board material.

  In recent years, electronic devices such as mobile phones, displays, and digital cameras have been rapidly reduced in size, weight, and thickness. Along with this, there is an increasing demand for flexible circuit boards that are excellent in folding resistance, lightweight and heat resistant. Among flexible circuit boards, in liquid crystal driver mounting applications for displays, in addition to bend resistance, weight reduction, and heat resistance, it is required that fine circuit patterns can be formed as the display becomes higher in definition.

  As a flexible circuit board material suitable for fine wiring pattern processing, a polyimide copper clad laminate using a copper foil having a thickness of 8 μm or less has been proposed. Such a thin copper foil is difficult to convey, and in order to handle the thin copper foil, a copper foil laminated on a carrier via a release layer is disclosed (for example, Patent Documents 1 and 2). reference).

On the other hand, with the recent increase in demand for flexible circuit board materials, improvement in productivity has become a major issue. So far, a method of simultaneously laminating a plurality of layers of metal foil and a heat-resistant adhesive film has been proposed (see, for example, Patent Document 3). Although this method makes it possible to manufacture a plurality of heat-resistant flexible laminates at the same time, there is a problem that adjacent copper foils rub against each other during lamination, resulting in appearance defects such as scratches, wrinkles, and wrinkles. It was.
Japanese Patent Laid-Open No. 2003-071984 JP 2002-316386 A JP 2003-001753 A

  In view of the above problems, an object of the present invention is to provide a method for dramatically and efficiently producing a laminated film with a metal layer having a good appearance.

  The present invention includes at least (1) a step of forming a laminate having a heat-resistant resin layer on both sides of a metal foil with a release layer having a metal layer on both sides of the release layer, and (2) the metal foil with a release layer being a release layer. It is the manufacturing method of the laminated | multilayer film with a metal layer characterized by including the process isolate | separated in this order.

  According to the present invention, the production efficiency of a laminated film with a metal layer can be dramatically improved, and a high-quality laminated film with a metal layer with reduced wrinkles and wrinkles can be obtained.

  The laminated film with a metal layer in the present invention has at least a metal layer and a heat resistant resin layer. The structure of the laminated film with a metal layer obtained by the present invention is shown in FIG. FIG. 1A shows a laminated film with a single-sided metal layer, and FIG. 1B shows a laminated film with a double-sided metal layer. A heat-resistant resin layer 103 is provided on one or both surfaces of the metal layer 101 with an adhesive resin layer 102 interposed therebetween as necessary.

  The present invention is characterized in that a metal foil with a release layer having a metal layer on both sides of the release layer is used in producing the laminated film with a metal layer having the above-described configuration. Thereby, when manufacturing a some laminated | multilayer film with a metal layer at once, rubbing of metal foil can be prevented, generation | occurrence | production of wrinkles and a blur can be suppressed, and a laminated | multilayer film with a favorable appearance can be manufactured. Although the manufacturing method of the laminated film with a metal layer of the present invention can be applied to a laminating method, a casting method, etc., the laminating method is preferably used from the viewpoint of manufacturing efficiency.

  Below, the manufacturing method of the laminated | multilayer film with a metal layer of this invention is demonstrated to a lamination method as an example. FIG. 2A shows an embodiment of a method for producing a laminated film with a single-sided metal layer, and FIG. 2B shows an embodiment of a method for producing a laminated film with a double-sided metal layer.

  This invention has the process of forming the laminated body which has a heat resistant resin layer on both surfaces of the metal foil with a peeling layer which has a metal layer on at least (1) both surfaces of a peeling layer.

  For example, in FIG. 2A, heat resistant resin layers 310 are disposed on both surfaces of a metal foil 311 with a release layer, and heated and pressed by a laminate roll 304. The surface of the heat resistant resin layer 310 may have an adhesive resin layer, and the metal layer of the metal foil with a release layer and the heat resistant resin layer may be laminated via the adhesive resin layer. it can. The structure of the laminated body obtained by the said process is shown to Fig.3 (a). The metal foil with a release layer has metal layers 101 on both sides of the release layer 104. Moreover, the heat resistant resin layer 103 is laminated | stacked on both surfaces of the metal foil with a peeling layer via the adhesive resin layer 102. FIG.

  In FIG. 2B, the heat-resistant resin layer 310 is disposed on both surfaces of the metal foil 311 with a release layer, and the metal foil 312 is disposed on the outer side of the metal foil 311. Here, an adhesive resin layer may be provided on both surfaces of the heat resistant resin layer 310, and the metal layer, the heat resistant resin layer, and the metal foil of the metal foil with the release layer are laminated through the adhesive resin layer. be able to. FIG. 3B shows the structure of the laminate obtained in the above step. The metal foil with a release layer has metal layers 101 on both sides of the release layer 104. A heat resistant resin layer 103 is laminated on both surfaces of the metal foil with a release layer via an adhesive resin layer 102. Further, a metal layer 101 is laminated on the outside via an adhesive resin layer 1020.

  The roll nip pressure during heating and pressurization is preferably 2 N / mm or more, more preferably 5 N / mm or more, and more preferably 10 N / mm or more in order to prevent poor adhesion and voids. On the other hand, in order to improve dimensional stability, the linear pressure is preferably 150 N / mm or less, more preferably 100 N / mm or less, and more preferably 80 N / mm or less. Moreover, it is also preferable to provide a protective film between the laminating roll and the laminated body from the viewpoint of preventing the oxidation of the metal foil surface and the uniformity of the heating and pressing during the heating and pressing. The material of the protective film is preferably one that can withstand a high temperature of 200 ° C. or higher. For example, a polyimide film is preferable.

  Next, (2) it has the process of isolate | separating the said metal foil with a peeling layer in a peeling layer. In order to suppress oxidation of the surface of the metal foil separated by the release layer, the temperature of the laminate during separation is preferably 200 ° C. or lower. In addition, this process (2) may be performed by providing a line different from the said process (1).

  For example, in FIG. 2A, a laminate obtained by heating and pressing with a laminate roll 304 is separated by a release layer with a release roll 305 and wound up as a laminated film 313 with a single-sided metal layer. Taking FIG. 3A as an example, two sets of laminated films with a single-sided metal layer having an adhesive resin layer 102 and a heat-resistant resin layer 103 on the metal layer 101 are manufactured simultaneously by separating with a release layer 104. be able to.

  Also in FIG. 2B, the laminate obtained by heating and pressing with the laminate roll 304 is separated by the release layer with the release roll 305 and wound up as a laminated film 314 with a double-sided metal layer. Taking FIG. 3B as an example, an adhesive resin layer 102, a heat-resistant resin layer 103, an adhesive resin layer 102, and a metal layer 101 are provided in this order on the metal layer 101 by separating with a release layer 104. Two sets of laminated films with double-sided metal layers can be produced simultaneously.

  In the present invention, it is not limited to the heating and pressurizing method having the above-described configuration, and more metal layers with release layers and heat-resistant resin layers can be simultaneously heated and pressed to simultaneously produce a multilayer film with metal layers. it can.

  When the peeling layer remains on the surface of the metal layer after peeling, it may be removed by etching treatment or polishing treatment.

  The surface of the metal layer after peeling is preferably subjected to an antioxidant treatment. As the antioxidant treatment, it is preferable to remove the release layer on the surface of the metal layer and to provide the antioxidant layer thereon. The antioxidant layer may be either organic or inorganic, and examples of the organic antioxidant layer include a layer containing a rust inhibitor including benzotriazole, a silane coupling agent, a titanate coupling agent, and the like. Moreover, metal layers, such as zinc, chromium, nickel, are mentioned as an inorganic type antioxidant layer.

  Next, the manufacturing method of the laminated film with a metal layer of the present invention will be described by taking a casting method as an example. For example, if necessary, an adhesive resin layer and a heat-resistant resin layer are applied and dried on both surfaces of the metal layer with a release layer, and these layers are cured. In order to remove the solvent from the adhesive resin layer and the heat-resistant resin layer, it is general to heat at about 60 to 200 ° C. continuously or intermittently for 0.5 to 60 minutes. Subsequently, in order to cure the adhesive resin layer and the heat-resistant resin layer, heat treatment is performed at a temperature of 200 to 400 ° C, preferably 240 to 350 ° C, more preferably 260 to 320 ° C for 0.5 to 48 hours. It is common to do. In addition, when it has multiple layers of these resin layers, the said application | coating, drying, and hardening process may be performed repeatedly, and a drying and hardening process may be processed collectively. After curing, a laminated film with a single-sided metal layer is obtained by separating the metal foil with a release layer.

  In both the laminating method and the casting method, the obtained laminated film with a metal layer may be further heat-treated. As a heat treatment method at this time, any one of a batch method treatment in which a laminated film with a metal layer is wound, a continuous treatment in a roll-to-roll method, and a single wafer treatment in a cut sheet may be used.

  Next, each layer will be described.

  First, the metal foil with a release layer has metal layers on both sides of the release layer. The release layer may be any structure that can release the metal layer after laminating the laminated film with the metal layer. As a method for obtaining a metal layer with a release layer, for example, a method in which an extremely thin organic layer is provided on a metal layer and a metal layer is formed thereon is generally used. In addition to the extremely thin organic layer, a method of forming a dissimilar metal or metal oxide is also included. When a copper layer is used as the metal layer, examples of the dissimilar metal include chromium, aluminum, iron, nickel, molybdenum, and zinc. Examples of the metal oxide include chromium, aluminum, iron, nickel, molybdenum, zinc, and copper oxides. The method for laminating the metal layer on the release layer may be any method that does not cause voids or abnormal peel force. Generally, plating is used. When the thickness of the release layer is as thin as 5 nm or less, even if the release layer is an insulator, a metal layer having a uniform thickness can be formed by plating with the release layer interposed therebetween. On the other hand, if the thickness of the release layer is 20 nm or more, a metal conductive layer may be formed on the release layer by electroless plating or dry plating, and a metal layer may be formed on the metal conductive layer by electrolytic plating. .

  The thickness of the metal foil with a release layer is, from the viewpoint of suppressing breakage and sag of the metal foil with a release layer when forming a laminate having a heat-resistant resin layer on both sides of the metal foil with a release layer by heating and pressing, etc. The total thickness is preferably 5 μm or more. The thickness of each metal layer is preferably 0.5 μm or more and 12 μm or less. If the thickness of each metal layer is 0.5 μm or more, it has sufficient electrical conductivity when forming a circuit. On the other hand, if it is 12 μm or less, the etching residue when the circuit is formed by the subtractive method can be reduced.

  In the present invention, the metal layer may be made of any metal species that can form a circuit. In general, copper or a copper alloy is used. This is because the solubility in an etching solution such as a ferric chloride solution or a cupric chloride solution is excellent, and electrical conductivity and thermal conductivity are high. Examples of the copper alloy include alloys with silver, zinc, bismuth, nickel, lead and the like. Furthermore, you may contain additives, such as phosphorus and sulfur. By these additives, there are effects such as improvement of thermal and electrical characteristics, improvement of etching property during circuit formation, and stable deposition in tin plating.

  When forming the fine wiring, the metal layer surface is preferably as smooth as possible in order to reduce the etching residue in the etching process. On the other hand, when the circuit pattern interval is large and the influence of the etching residue is small, the metal layer can be roughened. The adhesion with the heat resistant resin layer or the adhesive resin layer can be improved by the roughening treatment. The roughness (Rz) of the roughened surface is preferably 4 μm or less, and more preferably 2 μm or less. Considering formation of fine wiring, 1 μm or less is more preferable.

  It is desirable that both surfaces of the release layer-attached metal foil have been subjected to an antioxidant treatment. Thereby, the oxidation of the surface of the metal layer can be prevented, for example, in a process such as heating and pressing with the heat resistant resin layer or thermosetting of the heat resistant resin layer formed on the metal layer. Thus, by preventing the oxidation of the surface, the adhesive force between the metal layer and the heat resistant resin layer or the adhesive resin layer can be kept high. Any method can be used as long as the surface of the metal layer is not oxidized at a high temperature, particularly 200 to 400 ° C., and adhesion with the resin layer can be ensured. As an example, a method of forming a layer containing a metal or oxide such as chromium, zinc, nickel, molybdenum, titanium, or vanadium on the surface of the metal layer can be given. The antioxidant layer provided for the antioxidant treatment may be a single layer or a plurality of layers, and a plurality of metal species may be used. In order to further improve the adhesive strength, it is desirable that the outermost surface be treated with a silane coupling agent. The thickness of the antioxidant layer is preferably 3 nm or more, more preferably 5 nm or more from the viewpoint of the antioxidant effect. Moreover, from a viewpoint of suppressing the curvature by the crack of a metal layer, or internal stress, 100 nm or less is preferable and 50 nm or less is more preferable.

  In the laminated film with a metal layer of the present invention, examples of the heat resistant resin layer include acrylic resins, polyimide resins, polyamide resins, polyamideimide resins, polyetherimide resins, polyethersulfone resins, and polysulfone resins. Can be mentioned. Two or more of these may be included. In the present invention, a polyimide resin is preferably used from the viewpoint of heat resistance and insulation reliability. Moreover, you may use the film using these resins, and the heat resistant resin film comprised with a polyimide-type resin is used preferably. The heat resistance resin film may be subjected to an adhesive improvement treatment depending on the purpose. As the adhesion improving treatment, a discharge treatment such as a normal pressure plasma treatment, a corona discharge treatment, a low temperature plasma treatment or the like is preferable.

  Further, the total film thickness of the adhesive resin layer and the heat resistant resin layer is preferably 5 μm or more, more preferably 10 μm or more, and further preferably 20 μm from the viewpoint of handling properties. Considering the case where it is used for folding resistance and multilayer applications, the thickness is preferably 125 μm or less, more preferably 50 μm or less, and further preferably 40 μm or less.

  Specific examples of the polyimide resin include pyromellitic dianhydride, aromatic tetracarboxylic dianhydride selected from at least one selected from 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, p A polyimide resin synthesized from an aromatic diamine selected from at least one of -phenylenediamine, 4,4'-diaminobenzanilide, 4,4'-diaminodiphenyl ether, and 2,2'-dimethylbenzidine can be preferably used.

  Specific products of polyimide film include “Kapton” (registered trademark) manufactured by Toray DuPont Co., Ltd., “Upilex” (registered trademark) manufactured by Ube Industries, Ltd., and “Apical” (registered trademark) manufactured by Kaneka Corporation. ) And the like. When used as a flexible printed circuit board (FPC) material, “Kapton” (registered trademark) EN type is particularly preferably used from the viewpoints of adhesion, dimensional stability, and the like.

  You may have an adhesive resin layer on the surface of a heat resistant resin layer. The metal layer and the heat-resistant resin layer of the metal foil with a release layer can be laminated via this adhesive resin layer. As the adhesive resin layer, a thermosetting and / or thermoplastic resin can be used, and a thermoplastic resin is particularly preferable. Examples of the thermoplastic resin include acrylic resins, polyimide resins, polyamide resins, polyamideimide resins, polyetherimide resins, polyethersulfone resins, polysulfone resins, and the like. It may be used. In the present invention, a polyimide resin is preferably used from the viewpoint of heat resistance and insulation reliability.

  The adhesive resin layer can be formed, for example, by applying an adhesive to one or both surfaces of a heat resistant resin layer such as a heat resistant resin film and performing a heat treatment. For example, examples of the adhesive containing a polyimide resin include organic solvent-soluble polyimide resin compositions and polyimide precursor compositions. Hereinafter, the case where a polyimide precursor composition is used is demonstrated. For example, the polyimide precursor composition is applied on a heat resistant resin film, and the solvent is removed by heating continuously or intermittently at a temperature of about 60 to 200 ° C. for 0.5 to 60 minutes. At this time, it is common to apply | coat so that the film thickness after hardening may be 0.01-5 micrometers, Preferably it is 0.1-4 micrometers, More preferably, it is 0.5-3 micrometers.

  In the present invention, the heat resistant resin layer may contain other resins and fillers as long as the effects of the present invention are not impaired. Other resins include heat-resistant polymer resins such as acrylic resins, acrylonitrile resins, butadiene resins, urethane resins, polyester resins, polyamide resins, polyamideimide resins, epoxy resins, and phenol resins. Can be mentioned. Examples of the filler include organic or inorganic fine particles, fillers, and the like. Specific examples of the fine particles and filler include silica, alumina, titanium oxide, quartz powder, magnesium carbonate, potassium carbonate, barium sulfate, mica and talc.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

First, a polyimide resin for forming an adhesive resin layer was produced. The names of the abbreviations of acid dianhydride and diamine shown in the following production examples are as follows.
BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride SiDA: 1,1,3,3-tetramethyl-1,3-bis (3-aminopropyl) disiloxane DAE: 4,4 '-Diaminodiphenyl ether PDA: p-phenylenediamine NMP: N-methyl-2-pyrrolidone.

Production Example 1
In a reaction kettle equipped with a thermometer, a dry nitrogen inlet, a heating / cooling device using hot water / cooling water, and a stirring device, 62.15 g (0.25 mol) of DDA, 110.11 g (0.55 mol) of DAE, PDA After 21.62 g (0.2 mol) was charged together with 2765 g of NMP and dissolved, 294.2 g (1 mol) of BPDA was added. This was reacted at 70 ° C. for 6 hours to obtain a 15 wt% polyamic acid resin solution (PA1).

Production Example 2
In the same reaction vessel as in Production Example 1, 40.04 g (0.20 mol) of DAE and 86.48 g (0.8 mol) of PDA were charged together with 2384 g of NMP and dissolved, and then 294.2 g (1 mol) of BPDA was added. This was reacted at 70 ° C. for 6 hours to obtain a 15 wt% polyamic acid resin solution (PA2).

  An appearance evaluation method in each example and comparative example will be described.

  The wrinkle evaluation method is as follows. The laminated film with a single-sided metal layer was visually observed from the heat-resistant resin layer side, and the presence or absence of waviness due to streaky irregularities of the heat-resistant resin layer was observed. In the laminated film with a double-sided metal layer, the metal layer on one side was removed by etching and then evaluated in the same manner as the laminated film with a single-sided metal layer. If waviness due to streaks was observed, it was judged that wrinkles occurred.

  My evaluation method is as follows. The laminated film with a metal layer or the copper layer was visually observed, and the presence or absence of bending was observed. The number of bendings per 300 m length of the laminated film with a metal layer was defined as the number of times of bending. In addition, when a 300 m long laminated film with a metal layer could not be secured due to troubles such as copper foil breakage or raw material replacement, the cumulative number of occurrences per 300 m length was taken as the number of turns.

  The copper foil oxidation was evaluated by visually observing the surface of the laminated film with a metal layer, and if oxidation discoloration or streaks had occurred, it was determined that oxidation occurred.

  In the evaluation method for copper foil breakage, a 300 m long raw material was added to the heating and pressurizing step, and the number of times the copper foil breakage occurred was defined as the number of copper foil breakage.

Example 1
The polyamic acid resin solution PA1 is dried on one side of a 25 μm-thick polyimide film (“Kapton” (registered trademark) 100EN manufactured by Toray DuPont Co., Ltd., width 514 mm) that has been subjected to low-temperature plasma treatment in an argon atmosphere in advance. The film was coated with a reverse coater so that the film thickness was 2.0 μm, and dried at 80 ° C. for 10 minutes and further at 170 ° C. for 10 minutes to obtain a laminate of an adhesive resin layer / heat-resistant resin layer.

  After pickling the surface of the carrier copper foil of Micro Thin foil (Mitsui Metals Co., Ltd., carrier copper foil 18 μm / peeling layer / copper foil 1.5 μm, width 520 mm) as a metal foil with a release layer, zinc is used as an antioxidant layer. (10 nm), nickel (4 nm), and chromium (1 nm) were plated to obtain a metal foil with a release layer.

  Next, the resin layer was heated and pressed with a pair of 600 mmφ metal laminate rolls so that the adhesive resin layer was in contact with both surfaces of the metal foil with a release layer. The roll temperature was 350 ° C., the linear pressure was 50 N / cm, and the speed was 1.0 m / min. Note that “Kapton” 500H was used as a protective film for the metal roll. It peeled in the back | latter stage and obtained 2 rolls of laminated | multilayer films with a single-sided metal layer. In addition, the product temperature in the peeling part was 200 degrees C or less. There was no wrinkle, no wrinkles, and no oxidation was observed on the surface of the copper foil after peeling.

(Example 2)
As the metal foil with release layer, Micro Thin foil (Mitsui Metals Co., Ltd., carrier copper foil 18 μm / release layer / copper foil 1.5 μm, width 520 mm) was used as a raw material. First, the copper foil side surface was covered with a protective film, and only the carrier copper foil side was etched to a thickness of 5 μm. Furthermore, zinc (10 nm), nickel (4 nm), and chromium (1 nm) were plated on the clean etched surface as an antioxidant layer to obtain a metal foil with a release layer. Thereafter, the protective film was peeled off. Otherwise, a laminated film with a single-sided metal layer was produced in the same manner as in Example 1. There was no wrinkle, no wrinkles, and no oxidation was observed on the surface of the copper foil after peeling.

(Example 3)
After drying the polyamic acid resin solution PA1 on both surfaces of a 25 μm-thick polyimide film (“Kapton” (registered trademark) 100EN manufactured by Toray DuPont Co., Ltd., width 514 mm) that has been subjected to low-temperature plasma treatment in an argon atmosphere in advance. The film was coated with a reverse coater so that the film thickness was 2.0 μm, and dried at 80 ° C. for 10 minutes and further at 170 ° C. for 10 minutes to obtain a laminate of an adhesive resin layer / heat-resistant resin layer.

  As the metal foil with release layer, Micro Thin foil (Mitsui Metals Co., Ltd., carrier copper foil 18 μm / release layer / copper foil 1.5 μm, width 520 mm) was used as a raw material. First, the copper foil side surface was covered with a protective film, and only the carrier copper foil side was etched to a thickness of 5 μm. Furthermore, zinc (10 nm), nickel (4 nm), and chromium (1 nm) were plated on the clean etched surface as an antioxidant layer to obtain a metal foil with a release layer. Thereafter, the protective film was peeled off.

  Next, the metal layer (NA-DFF foil: manufactured by Mitsui Mining & Smelting Co., Ltd.) so that the adhesive resin layer is in contact with both surfaces of the metal foil with the release layer, and the antioxidant layer is further in contact with the upper and lower sides of the resin layer. (Thickness 9 μm, width 520 mm) were arranged and heated and pressed with a pair of 300 mmφ metal laminate rolls. The roll temperature was 350 ° C., the linear pressure was 50 N / cm, and the speed was 1.0 m / min. In addition, Kapton 500H was used for the metal roll as a protective film. It peeled in the back | latter stage and obtained 2 rolls of laminated | multilayer film with a double-sided metal layer. In addition, the product temperature in the peeling part was 200 degrees C or less. There was no wrinkle, no wrinkles, and no oxidation was observed on the surface of the copper foil after peeling.

Example 4
As a metal foil with a release layer, a Micro Thin foil (Mitsui Metals Co., Ltd., carrier copper foil 18 μm / release layer / copper foil 3.0 μm, width 520 mm) was used as a raw material. First, only the carrier copper foil side was etched by the method described in Example 2 to a thickness of 3.0 μm. Furthermore, zinc (10 nm), nickel (4 nm), and chromium (1 nm) were plated on the clean etched surface as an antioxidant layer to obtain a metal foil with a release layer. Thereafter, the protective film was peeled off. Otherwise, a laminated film with a single-sided metal layer was produced in the same manner as in Example 1. Neither wrinkles nor wrinkles occurred, and no oxidation was observed on the copper foil surface after peeling.

(Example 5)
As a metal foil with a release layer, a Micro Thin foil (manufactured by Mitsui Kinzoku Co., Ltd., carrier copper foil 18 μm / release layer / copper foil 2.0 μm, width 520 mm) was used as a raw material. First, only the carrier copper foil side was etched by the method of Example 2 to a thickness of 2.0 μm. Furthermore, zinc (10 nm), nickel (4 nm), and chromium (1 nm) were plated on the clean etched surface as an antioxidant layer to obtain a metal foil with a release layer. Thereafter, the protective film was peeled off. Otherwise, a laminated film with a single-sided metal layer was produced in the same manner as in Example 1. Neither wrinkles nor wrinkles occurred, and the copper foil surface after peeling did not oxidize, but the copper foil was cut irregularly and a product of sufficient length could not be obtained.

(Example 6)
A product was obtained in the same manner as in Example 1 except that the temperature of the product at the time of peeling was 250 ° C. Although wrinkles and wrinkles did not occur, discoloration due to oxidation was observed on the surface of the copper foil after peeling.

(Example 7)
PA2 was applied to one side of the metal foil with a release layer produced in Example 1 with a comma coater so that the film thickness after drying and curing was 30 μm, and dried at 80 ° C. for 10 minutes and further at 230 ° C. for 10 minutes. Next, PA2 was similarly applied to the other surface and dried at 80 ° C. for 10 minutes and further at 170 ° C. for 10 minutes to obtain a laminate. Next, this laminate was thermally cured continuously at 350 ° C. for 1 hour in nitrogen. After cooling this laminated body to 25 degreeC, it isolate | separated and wound up in the peeling layer, and obtained two rolls of the laminated | multilayer film with a metal layer. Neither wrinkles nor wrinkles occurred, and the copper foil surface was not oxidized.

(Comparative Example 1)
Instead of the metal foil with a release layer, two copper foils (NA-DFF foil manufactured by Mitsui Kinzoku Mining Co., Ltd .: 9 μm) are used with the antioxidant layer on the outside, and other conditions are the same as in Example 1. It was. Wrinkles occurred on the entire surface, and I occurred at 10 locations / 300 m. The product was unusable. In addition, oxidation occurred on the surface of the copper foil.

(Comparative Example 2)
Only the resist surface (the reverse side of the antioxidant layer) of the copper foil (NA-DFF foil manufactured by Mitsui Kinzoku Mining Co., Ltd.) was half-etched to a thickness of 5 μm. A trial production was performed in the same manner as in Comparative Example 1 using two copper foils. Wrinkles occurred on the entire surface, and I generated 50 spots / 300 m. In addition, copper foil breakage occurred irregularly, and a product with a sufficient length could not be obtained. Also, oxidation occurred on the surface of the copper foil.

(Comparative Example 3)
Only the resist surface (the reverse side of the antioxidant layer) of copper foil (Mitsui Metals Mining Co., Ltd. NA-DFF foil: 9 μm) was half-etched to produce a copper foil with a thickness of 3.0 μm. Thus, copper foil was frequently cut and could not be produced.

  Table 1 shows the results of Examples 1 to 7 and Comparative Examples 1 to 3.

  In the method of stacking two copper foils as in the comparative example, wrinkles and wrinkles frequently occurred. On the other hand, in the present invention, it was shown that a thin film with a particularly thin metal layer can be efficiently produced with high quality.

  The laminated film with a metal layer obtained by the production method of the present invention is particularly suitable for a material for a flexible circuit board of an electronic device such as a mobile phone, a display and a digital camera.

Schematic showing an embodiment of the structure of a laminated film with a metal layer Schematic showing an embodiment of the method for producing a laminated film with a metal layer of the present invention Schematic showing an embodiment of the structure of a laminate having a heat-resistant resin layer on both sides of a metal foil with a release layer

Explanation of symbols

101: Metal layer 102: Adhesive resin layer 103: Heat resistant resin layer 104: Release layer 301: Film unwinding shaft (upper)
302: Film unwinding shaft (bottom)
303: Metal foil unwinding shaft 304 with release layer 304: Laminate roll 305: Release roll 306: Winding shaft 307: Copper foil unwinding shaft (top)
308: Copper foil unwinding shaft (bottom)
310: heat-resistant resin layer 311: metal foil with release layer 312: metal foil 313: laminated film with single-sided metal layer 314: laminated film with double-sided metal layer

Claims (5)

At least (1) a step of forming a laminate having a heat-resistant resin layer on both sides of a metal foil with a release layer having a metal layer on both sides of the release layer, and (2) separating the metal foil with a release layer at the release layer. The manufacturing method of the laminated | multilayer film with a some metal layer characterized by including a process in this order. 2. The method for producing a laminated film with a metal layer according to claim 1, wherein in the step (2), the temperature of the laminate is 200 ° C. or less and the metal foil with a release layer is separated by the release layer. . The method for producing a laminated film with a metal layer according to claim 1 or 2, wherein an antioxidation treatment is applied to both surfaces of the metal foil with a release layer. The step (1) is a step of heating and pressurizing the metal foil with a release layer and the heat-resistant resin layer through the adhesive resin layer. A method for producing a laminated film. 5. The method for producing a laminated film with a metal layer according to claim 1, wherein the thickness of the metal foil with a release layer is 5 μm or more, and the thickness of each metal layer is 0.5 to 12 μm. .

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