JP2007296734A - Flexible metal clad laminate excellent in dimensional stability and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a dimensional change when a flexible metal-clad laminate with the dimensional change suppressed during the processing of a printed wiring board, especially even when it is a half mill article, is manufactured by a lamination method and to eliminate a defective appearance such as wrinkles and defective appearance after metal etching. <P>SOLUTION: A film-shaped joining member 5-15 μm in total thickness in which an adhesive layer containing a thermoplastic polyimide is formed on one side or both sides of a polyimide film, when metal foil and an adhesive joining member are laminated by a heat roll lamination device having at least a pair of metal rolls, the tension of a film-shaped lamination member is made 0.1-1 N/cm. Before the metal foil and the adhesive joining member are laminated, an arrow-shaped shaft having at least one rotor is brought into contact to each other. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a flexible metal-clad laminate having excellent dimensional stability and a method for producing the same, and in particular, a film-like joining member in which an adhesive layer containing a thermoplastic polyimide is formed on one or both sides of a polyimide film. The present invention relates to a flexible metal-clad laminate having excellent dimensional stability obtained by bonding a metal foil and a method for producing the same.

  In recent years, the demand for various printed circuit boards has increased with the reduction in weight, size, and density of electronic products. In particular, the demand for flexible laminated boards (hereinafter referred to as “FPC”) is particularly high. It is growing. The FPC has a structure in which a circuit made of a metal foil is formed on an insulating film.

  The FPC is generally made of various insulating materials, and is manufactured by a method in which a flexible insulating film is used as a substrate, and a metal foil is bonded to the surface of the substrate by heating and pressure bonding through various adhesive materials. Is done. A polyimide film or the like is preferably used as the insulating film.

  As the adhesive material, epoxy-based, acrylic-based thermosetting adhesives are generally used. An FPC using such a thermosetting adhesive has a three-layer structure of substrate / adhesive material / metal foil, and is also referred to as “three-layer FPC”.

  The thermosetting adhesive has an advantage that it can be bonded at a relatively low temperature. However, as the requirements for various characteristics such as heat resistance, flexibility, and electrical reliability become stricter for FPC in the future, it is considered that the three-layer FPC using a thermosetting adhesive becomes difficult to cope with.

  Therefore, in recent years, FPCs in which a metal layer is directly provided on an insulating film or a thermoplastic polyimide is used for an adhesive layer have been proposed. Such an FPC is also called a two-layer FPC because a metal layer is directly formed on an insulating substrate. This two-layer FPC has characteristics superior to those of the three-layer FPC and can sufficiently meet the demands for the various characteristics described above, so that demand is expected to increase in the future.

  As a method for producing a flexible metal-clad laminate for use in a two-layer FPC, for example, (1) a casting method in which polyamic acid, which is a polyimide precursor, is cast or applied onto a metal foil and then imidized; 2) A metallizing method in which a metal layer is directly formed on a polyimide film by sputtering or plating, and (3) a laminating method in which a polyimide film and a metal foil are bonded via a thermoplastic polyimide.

  Among these, the lamination method is superior in that the thickness range of the metal foil that can be handled is wider than that of the casting method and the apparatus cost is lower than that of the metalizing method. As a laminating apparatus, a hot roll laminating apparatus or a double belt press apparatus that continuously laminates a roll-shaped material is used. Among the above, from the viewpoint of productivity, a thermal laminating method using a hot roll laminating apparatus can be more preferably used.

  When a conventional three-layer FPC was produced by a laminating method, a thermosetting resin was used for the adhesive layer, so that the laminating temperature could be less than 200 ° C. (see Patent Document 1). On the other hand, in the two-layer FPC, since thermoplastic polyimide is used as the adhesive layer, it is necessary to apply a high temperature of 200 ° C. or higher, and in some cases, close to 400 ° C., in order to exhibit heat-fusibility. Therefore, residual distortion occurs in the flexible metal-clad laminate obtained by laminating, and it appears as a dimensional change when wiring is formed by etching and when solder reflow is performed to mount components.

  In particular, as an example of a laminating method, when an adhesive layer containing a thermoplastic polyimide is provided on a polyimide film, the polyamide acid which is a precursor of the thermoplastic polyimide is cast or applied, and then continuously heated. There is a method in which imidization is performed and a metal foil is bonded, but in this case, since heating and pressurization are continuously performed, the material is often placed in a heating environment under tension. Therefore, different thermal stresses are generated in the MD direction and the TD direction. Specifically, a pulling force acts in the MD direction where tension is applied, and conversely, a shrinking force acts in the TD direction. As a result, when the metal foil is etched from the flexible laminate and when heated through solder reflow, this distortion is released and contracts in the MD direction and conversely expands in the TD direction. This dimensional change becomes more remarkable as the thickness of the adhesive film is reduced.

  By the way, in recent years, in order to achieve miniaturization and weight reduction of electronic devices, wiring provided on a substrate has been miniaturized, and components to be mounted are mounted with miniaturized and high-density components. . Therefore, for FPC, in order to improve the foldability and bending resistance, which are features of FPC, there is an increasing demand for a flexible metal-clad laminate having a thinner insulating layer.

  However, as described above, since the thermal laminating method is easily affected by dimensional changes, the dimensional change is large when a flexible metal-clad laminate is manufactured by the thermal laminating method. That is, there is a problem that the dimensional change of the flexible metal-clad laminate after forming the fine wiring is large, and the component and the board are not well connected due to deviation from the component mounting position at the design stage.

  Therefore, attempts have been made to suppress dimensional changes by using a protective film during laminating or by pre-drying the adhesive film before being used for laminating (see Patent Document 2 or 3).

  Specifically, in Patent Document 2, a step of placing a protective film between at least one pair of press rolls and pressurizing and heating the metal foil and the heat-resistant adhesive film, and the obtained laminate The dimensional change rate is reduced by producing an FPC using a method including a step of cooling while lightly adhering to the protective film and a step of peeling the protective film from the laminate.

Moreover, in the said patent document 3, in the manufacture process of FPC, in order to remove the water | moisture content in an adhesive film before a lamination, an adhesive film is dried beforehand, and it heat-laminates in that state, and is uneven pattern on the surface of a laminated board. It is trying not to occur.
Japanese Patent Laid-Open No. 9-199830 (published July 31, 1997) JP 2002-326308 A (published on November 12, 2002) JP 2002-326280 A (published on November 12, 2002)

  The thickness of the insulating layer used in the current two-layer FPC is mainly 25 μm (1 mil), but the thickness of the insulating layer is reduced to 12 to 15 μm due to further reduction of the board mounting space and problems such as springback. The so-called “half-mill” demand has begun to appear.

  However, since the thickness of the adhesive film is thin, the half mill product is more susceptible to thermal stress during lamination, and the techniques of Patent Document 2 and Patent Document 3 are insufficient in improving the dimensional change sufficiently. There is. Therefore, even when high dimensional accuracy is required in a half mill product, development of a further dimensional change suppression technology that can be applied is required.

  The present inventor has already found a technique capable of satisfactorily suppressing a dimensional change even when a thin adhesive film is used when a film and a copper foil are laminated by a hot roll laminating method. In Japanese Patent Application No. 2000-237200, the dimensional change is suppressed by lowering the tension applied to the film-like joining member during hot roll lamination. Further, the present inventors have found a method capable of effectively suppressing the appearance of the obtained metal-clad laminate and the voids (appearance after metal etching) generated inside the metal-clad laminate.

  The present invention has been made in view of the above problems, and the purpose thereof is a flexible metal-clad laminate in which the occurrence of dimensional changes is suppressed during printed wiring board processing, particularly a half-mill product, An object of the present invention is to provide a flexible metal-clad laminate in which the occurrence of dimensional change is suppressed when produced by a laminating method, and there are no appearance defects such as wrinkles and no appearance defects after metal etching, and a method for producing the same.

As a result of intensive studies in view of the above problems, the present inventors have found that the above problems can be solved by the following novel manufacturing method. That is, (a) (1) Using a hot roll laminating apparatus having a pair of metal rolls, a metal foil and a total thickness of 5 to 5 are formed with an adhesive layer containing thermoplastic polyimide on one or both sides of a polyimide film. A step of laminating and bonding a film-like joining member of 15 μm with a tension applied to the film-like joining member in a range of 0.01 to 1 N / cm;
(2) A method for producing a flexible metal-clad laminate comprising the step of bringing an arcuate shaft having one or more rotating bodies into contact with the film-like joining member prior to the step (1).
(B) The flexible metal-clad laminate according to claim 1, wherein in the step (a), a protective film is used and thermal lamination is performed with a tension applied to the protective film in a range of 600 to 2000 N / m. A manufacturing method of a board.
(C) Before subjecting the protective film to thermal lamination, the surface temperature of the protective film during thermal lamination is brought into contact with the thermal roll by bringing the thermal film into contact with the thermal roll. The method for producing a flexible metal-clad laminate according to claim 1 or 2, further comprising a step of heat laminating within the range of the surface temperature.
(D) The method for producing a flexible metal-clad laminate according to any one of (a) to (c), wherein the heating temperature during heat lamination is 300 ° C to 500 ° C.
About.

  As described above, in the flexible metal-clad laminate according to the present invention, in the manufacturing process, the tension applied to the film-like joining member at the time of thermal lamination is regulated to low tension (0.01 to 1 N / m), and thermal lamination is performed. Prior to this, an arcuate shaft having a large number of rotating bodies is pressed against the film-like joining member. Therefore, even if the thickness of the film-like joining member is thin (specifically 5 to 15 μm), the dimensional stability, particularly the dimensional stability in the laminating method is excellent, and the appearance of the metal-clad laminate is excellent. . Further, the flexible metal-clad laminate according to the present invention is capable of suppressing the occurrence of defects in appearance such as wrinkles because the tension is cut before thermal lamination in the production process. Therefore, there is an effect that the dimensional stability, particularly the dimensional stability in the laminating method is excellent.

  An embodiment of the present invention will be described as follows, but the present invention is not limited to this.

<I. Film-like joining member>
The film-like joining member according to the present invention is obtained by using a polyimide film as a core film and forming an adhesive layer containing thermoplastic polyimide on one side or both sides of the polyimide film. The total thickness of the film-like joining member is preferably 5 to 15 μm. In this invention, when the thickness of a film-like joining member is thin, a remarkable effect is expressed.

<I-1. Polyimide film>
In the film-like joining member according to the present invention, the polyimide film used as the core film is manufactured using polyamic acid as a precursor. Any known method can be used as a method for producing the polyamic acid. For example, a polyamic acid organic polar solvent solution (hereinafter also referred to as “polyamic acid solution”) obtained by dissolving a substantially equimolar amount of an aromatic dianhydride and an aromatic diamine in an organic polar solvent. It can be produced by stirring under controlled temperature conditions until polymerization of the acid dianhydride and diamine is completed. The polyamic acid concentration of the polyamic acid solution thus produced is usually 5 to 35% by weight, preferably 10 to 30% by weight. When the concentration is within this range, a molecular weight and a solution viscosity suitable for the present invention can be obtained.

  As the polymerization method of the polyamic acid, any known method and a combination thereof can be used. The characteristic of the polymerization method in the polymerization of polyamic acid is the order of addition of the monomers. That is, various physical properties of the obtained polyimide can be controlled by controlling the order of addition of the monomers. Therefore, in the present invention, any monomer addition method may be used in the polyamic acid polymerization method.

As described above, the polyamic acid polymerization method is not particularly limited, but typical polymerization methods include the following methods.
(1) A method in which an aromatic diamine is dissolved in an organic polar solvent and reacted with a substantially equimolar amount of an aromatic tetracarboxylic dianhydride for polymerization.
(2) An aromatic tetracarboxylic dianhydride is reacted with a small molar amount of an aromatic diamine compound in an organic polar solvent to obtain a prepolymer having acid anhydride groups at both ends. Subsequently, a method of polymerizing using an aromatic diamine compound so that the aromatic tetracarboxylic dianhydride and the aromatic diamine compound are substantially equimolar throughout all the steps.
(3) An aromatic tetracarboxylic dianhydride is reacted with an excess molar amount of an aromatic diamine compound in an organic polar solvent to obtain a prepolymer having amino groups at both ends. Subsequently, the aromatic tetracarboxylic dianhydride is added so that the aromatic tetracarboxylic dianhydride and the aromatic diamine compound are substantially equimolar throughout the entire process after the addition of the aromatic diamine compound. A method of polymerizing using a product.
(4) A method in which an aromatic tetracarboxylic dianhydride is dissolved and / or dispersed in an organic polar solvent and then polymerized using an aromatic diamine compound so as to be substantially equimolar.
(5) A method of polymerizing by reacting a substantially equimolar mixture of an aromatic tetracarboxylic dianhydride and an aromatic diamine in an organic polar solvent.

  Note that these methods may be used alone or in combination.

  The organic polar solvent used for polymerizing the polyamic acid is not particularly limited as long as it dissolves the polyamic acid, and any solvent can be used. For example, amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like, and N, N-dimethylformamide and N, N-dimethylacetamide are particularly preferred. It can be preferably used.

  Here, the component used for the organic polar solvent solution (polyamic acid solution) containing the polyamic acid concerning this invention, ie, a polyimide precursor, is demonstrated.

  The tetracarboxylic dianhydride that can be used as the acid dianhydride component of the polyamic acid solution according to the present invention is not particularly limited. For example, pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 1,2,5,6 -Naphthalenetetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic dianhydride, 4,4'- Oxyphthalic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ) Propane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (2,3- Dicarboxyphenyl) Tan dianhydride, bis (3,4-dicarboxyphenyl) ethane dianhydride, oxydiphthalic dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, p-phenylenebis (trimellitic acid mono Ester acid anhydride), ethylene bis (trimellitic acid monoester acid anhydride), and bisphenol A bis (trimellitic acid monoester acid anhydride), and the like. These compounds can be preferably used alone or as a mixture mixed at an arbitrary ratio.

  Among these tetracarboxylic dianhydrides, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride, 4,4′-oxyphthalic dianhydride, and 3 , 3 ′, 4,4′-biphenyltetracarboxylic dianhydride is preferably selected and used.

The diamine that can be used as the diamine component of the polyamic acid solution according to the present invention is not particularly limited. For example, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylmethane, benzidine, 3,3'-dichlorobenzidine, 3,3'-dimethylbenzidine, 2,2'-dimethylbenzidine, 3,3'- Dimethoxybenzidine, 2,2′-dimethoxybenzidine, 4,4′-diaminodiphenylsulfide, 3,3′-diaminodiphenylsulfone, 4,4′-diaminodiphenylsulfone, 4,4′-oxydianiline, 3,3 '-Oxydianiline, 3,4'-oxydianiline, 1,5-diaminonaphthalene, 4,4'-diaminodiphenyldiethylsilane, 4,4'-diaminodiphenylsilane, 4,4'-diaminodiphenylethylphosphine Oxide, 4,4′-diaminodiphenyl N-methylamine, 4,4′-diaminodiphenyl N-sulfate Phenylamine, 1,4-diaminobenzene (p-phenylenediamine), 1,3-diaminobenzene, 1,2-diaminobenzene, bis {4- (4-aminophenoxy) phenyl} sulfone, bis {4- (3- Aminophenoxy) phenyl} sulfone, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-bis (3-aminophenoxy) biphenyl, 1,3-bis (3-aminophenoxy) benzene, 1, 3-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 3,3′-diaminobenzophenone, 4,4′- Diaminobenzophenone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, and the like Can be mentioned.

  The polyimide film according to the present invention can be obtained by appropriately determining the type of aromatic tetracarboxylic dianhydride and aromatic diamine, and the blending ratio so as to obtain a film having desired characteristics. it can.

  Moreover, a filler can be added to the polyimide film concerning this invention in order to improve the various characteristics of films, such as slidability and heat conductivity. The filler used in the present invention is not particularly limited, and for example, silica, titanium oxide, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, mica, and the like can be suitably used.

  Since the particle diameter of the filler used in the present invention is determined by the film characteristics to be modified and the kind of filler to be added, it is not particularly limited, but the average particle diameter is 0.05 to 100 μm. Is more preferable, 0.1 to 75 μm is more preferable, 0.1 to 50 μm is further preferable, and 0.1 to 25 μm is particularly preferable. If the particle diameter is within the above range, a large modification effect can be obtained, and the film does not significantly impair the surface property, and the mechanical properties of the film are not greatly deteriorated. Also, the number of added parts of the filler is not particularly limited because it is determined by the film characteristics to be modified, the filler particle diameter, and the like. That is, it is sufficient that the modification effect by the filler appears and the mechanical properties of the film are not impaired. Specifically, it is preferably 0.01 to 100 parts by weight, more preferably 0.01 to 90 parts by weight, and 0.02 to 80 parts by weight with respect to 100 parts by weight of polyimide. Is more preferable.

The addition of the filler is not particularly limited, and specific examples include the following methods.
(A) A method of adding to the polymerization reaction solution before or during the polymerization.
(B) A method in which the filler is kneaded using three rolls after completion of the polymerization.
(C) A method of preparing a dispersion containing a filler and mixing it with a polyamic acid solution.

  Among these methods, (C) a method of mixing a dispersion containing a filler with a polyamic acid solution is preferable, and a method of mixing a dispersion containing a filler with a polyamic acid solution immediately before film formation is particularly preferable. By adopting this method, the filler can be mixed immediately before forming the film, so that contamination by the filler in the film production line can be minimized.

  When preparing a dispersion containing the above filler, it is preferable to use the same solvent as the polyamic acid polymerization solvent as the solvent for the dispersion. Moreover, in order to disperse | distribute a filler favorably and stabilize a dispersion state, a dispersing agent, a thickener, etc. can also be used in the range which does not affect a film physical property.

<I-2. Manufacturing method of polyimide film>
It does not specifically limit about the method of manufacturing a polyimide film from the above-mentioned polyamic-acid solution, A conventionally well-known method can be used. Specifically, a thermal imidization method and a chemical imidization method are given as representative examples, but either method may be used to produce a film. In particular, the use of the chemical imidation method tends to provide a polyimide film having various properties that are preferably used in the present invention.

Moreover, although the structure of the manufacturing method of the polyimide film concerning this invention is not specifically limited, It is preferable that the following four processes are included.
(A) A step of reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride in an organic solvent to obtain a polyamic acid solution.
(B) A step of casting a film-forming dope containing the polyamic acid solution on a support.
(C) A step of peeling the gel film from the support after heating the film-forming dope on the support.
(D) A step of further heating the gel film to imidize and dry the remaining amic acid.

  The film-forming dope in the step (b) includes a dehydrating agent typified by an acid anhydride such as acetic anhydride, and an imidization catalyst typified by a tertiary amine such as isoquinoline, β-picoline, pyridine and the like. A curing agent may be added.

  Hereinafter, taking the case of using the chemical imide method as an example, the production steps of the polyimide film according to the present invention (the above steps (b) to (d)) will be described. However, the present invention is not limited to the following examples. The film forming conditions and heating conditions should be appropriately changed depending on the type of polyamic acid, the thickness of the film, and the like, and are not limited to the following examples. In addition, about the said process (a), <I-1. Since it was described in detail in the section “Polyimide film>, it is omitted here.

  In the steps (b) and (c), the dehydrating agent and the imidization catalyst are mixed at a low temperature into the polyamic acid solution prepared in the step (a) to obtain a film forming dope. Subsequently, the film-forming dope is cast into a film on a support such as a glass plate, an aluminum foil, an endless stainless steel belt, or a stainless steel drum. Then, it heats on a support body at a temperature range of 80 to 200 ° C., preferably 100 to 180 ° C. As a result, the dehydrating agent and imidization catalyst are activated and partial curing and / or drying occurs. Then, it peels from a support body and a polyamic-acid film (henceforth a "gel film") is obtained.

  The gel film is in an intermediate stage of curing from polyamic acid to polyimide, has a self-supporting property, and the volatile content of the gel film is preferably in the range of 5 to 500% by weight, More preferably within the range of 200% by weight, even more preferably within the range of 5 to 150% by weight. By using a gel film with a volatile content within this range, problems such as film breakage, film color unevenness due to uneven drying, and characteristic variations that occur during firing (step (d) above) are avoided. Can do.

The volatile content of the gel film is expressed by the following formula (1)
(AB) × 100 / B (1)
(In the formula, A represents the weight of the gel film, and B represents the weight after heating the gel film at 450 ° C. for 20 minutes.)
Can be used to calculate.

  The addition amount of the dehydrating agent is preferably in the range of 0.5 to 5 mol, more preferably in the range of 1.0 to 4 mol, with respect to 1 mol of the amic acid unit in the polyamic acid. preferable. Moreover, it is preferable that the addition amount of an imidation catalyst exists in the range of 0.05-3 mol with respect to 1 mol of amic acid units in a polyamic acid, and exists in the range of 0.2-2 mol. Is more preferable.

  By making the addition amount of the dehydrating agent and the imidization catalyst within the above range, chemical imidization completely occurs, and there is no breakage during the firing or mechanical strength is not lowered. Furthermore, the progress of imidization does not become too fast and it becomes difficult to cast into a film.

  In the step (d), the end of the gel film is fixed to avoid shrinkage during curing, and water, residual solvent, residual conversion agent and imidation catalyst are removed, and the remaining amic acid is removed. A polyimide film is obtained by complete imidization.

  At this time, it is preferable to heat the polyimide film so that the maximum baking temperature is 400 to 650 ° C. for 5 to 400 seconds. If the maximum firing temperature is “above this temperature” and / or “long time”, the problem of thermal degradation of the film may occur. Conversely, if “below this temperature” and / or “short time”, the predetermined effect may not be exhibited.

  Further, depending on the molecular structure and characteristics of the film, the dimensional change during heating can be adjusted during the heat treatment.

  Various characteristics of the polyimide film can be appropriately controlled depending on the type of monomer used, the order of addition of the monomers during polymerization, the imidization method selected, and the like.

<I-3. Adhesive layer and thermoplastic polyimide used in it>
The structure of the adhesive layer used for the film-like joining member according to the present invention is not particularly limited, and includes any one of acrylic, epoxy, modified epoxy, phenol, polyamideimide, and polyimide. May be. In particular, from the viewpoints of heat resistance, insulation reliability, laminate processability, solder heat resistance, and electrical reliability, it is preferable to use an adhesive layer mainly composed of thermoplastic polyimide.

  In this specification, “thermoplastic polyimide” has a glass transition temperature and is 10 to 400 ° C. (increase) in thermomechanical analysis (TMA) in compression mode (probe diameter 3 mmφ, load 5 g). (Temperature rate: 10 ° C./min) means that permanent compression deformation occurs in the temperature range.

  As the thermoplastic polyimide contained in the adhesive layer, thermoplastic polyimide, thermoplastic polyamideimide, thermoplastic polyetherimide, thermoplastic polyesterimide, and the like can be suitably used.

  In view of the fact that lamination with an existing apparatus is possible and the heat resistance of the resulting metal-clad laminate is not impaired, the thermoplastic polyimide according to the present invention has a glass transition temperature in the range of 150 to 300 ° C. (Hereinafter also referred to as “Tg”). In addition, Tg can be calculated | required from the value of the inflexion point of the storage elastic modulus measured with the dynamic viscoelasticity measuring apparatus (DMA).

  The polyamic acid that is a precursor of the thermoplastic polyimide used in the present invention is not particularly limited, and any polyamic acid can be used. Further, regarding the production of the polyamic acid solution, the above <I-1. The production method of the polyamic acid solution described in the section “Polyimide film> can be used in exactly the same manner.

  Furthermore, various characteristics of the polyamic acid can be adjusted by various combinations of raw materials used. In general, when the ratio of the diamine having a rigid structure is increased, “the glass transition temperature is increased” and / or “the storage elastic modulus is increased during heating”, and therefore the adhesiveness and workability are decreased. Therefore, the ratio of the diamine having a rigid structure is preferably 40 mol% or less, more preferably 30 mol% or less, and particularly preferably 20 mol% or less.

  In the present specification, the “diamine having a rigid structure” refers to a diamine having a rigid structure having no flexibility in the main chain between two NH 2 groups.

  In addition, an inorganic or organic filler may be added to the adhesive layer as necessary, and the above-described method can be used in the same manner as the method for adding the filler.

<II. Flexible metal-clad laminate>
The flexible metal-clad laminate according to the present invention is obtained by laminating the film-like joining member and the metal foil.

  In the flexible metal-clad laminate according to the present invention, the dimensional change rate before and after heating for 30 minutes at 250 ° C. after removing the metal foil is −0.10 to + 0.10% in both the MD direction and the TD direction. It is highly preferred that it is in the range. The dimensional change rate before and after heating is represented by a ratio between a predetermined dimension in the flexible metal-clad laminate after the etching process and a predetermined dimension difference after the heating process and a predetermined dimension after the etching process.

  When the dimensional change rate is within the above range, the defective rate at the time of component mounting can be reduced in the flexible metal-clad laminate.

  The method for measuring the rate of dimensional change is not particularly limited, and any conventionally known method can be used as long as it is a method capable of measuring the increase / decrease in dimensions occurring before and after the heating step in the flexible metal-clad laminate. be able to.

  Here, it is preferable to measure the dimensional change rate in both the MD direction and the TD direction. In the case of continuous imidization and lamination, since the tension is different in the MD direction and the TD direction, a difference appears in the degree of thermal expansion / contraction and the dimensional change rate also differs.

  Therefore, a material having a small dimensional change rate is required to have a small dimensional change rate in both the MD direction and the TD direction. In the present invention, after removing the metal foil from the flexible metal-clad laminate, the dimensional change rate before and after heating at 250 ° C. for 30 minutes is −0.10 to + 0.10% in both the MD direction and the TD direction. It is highly preferred that it is in the range.

  In addition, in the heating process at the time of measuring the dimensional change rate, it is sufficient that heating is performed at 250 ° C. for 30 minutes, and other specific conditions are not particularly limited.

  The metal foil used in the present invention is not particularly limited, but when the flexible metal-clad laminate of the present invention is used for electronic equipment / electric equipment, for example, copper or copper alloy, stainless steel or its Mention may be made of alloys, nickel or nickel alloys (including 42 alloys), or foils made of aluminum or aluminum alloys.

  In a general flexible metal-clad laminate, copper foil such as rolled copper foil or electrolytic copper foil is frequently used, but these copper foils can also be preferably used in the present invention. In addition, the antirust layer, the heat-resistant layer, or the contact bonding layer may be apply | coated to the surface of these metal foil.

  In the present invention, the thickness of the metal foil is not particularly limited, and may be any thickness as long as a sufficient function can be exhibited depending on the application. However, when the thickness of the metal foil is too thin, there is a tendency that connection failure or connection reliability is liable to be lowered during mounting on various substrates using an anisotropic conductive film or the like. On the contrary, if the thickness of the metal foil is too thick, it tends to be difficult to form fine wiring. Therefore, in general, the thickness of the metal foil is preferably 1 to 35 μm, more preferably 2 to 25 μm, and particularly preferably 3 to 18 μm.

  Moreover, after laminating using a thick metal foil, the thickness of the metal foil can be reduced by a known method such as etching.

<IV. Manufacturing method of flexible metal-clad laminate>
In a flexible metal-clad laminate containing polyimide, as a method of bonding a polyimide film and a metal foil, for example, (i) after forming an adhesive layer on at least one side of the polyimide film, a method of bonding to the metal foil, (Ii) A method in which an adhesive layer is formed into a sheet shape and bonded to the polyimide film, and then bonded to a metal foil; or (iii) an adhesive layer is formed into a sheet shape and the metal foil is bonded to the polyimide film. For example, a method of laminating and attaching to each other can be suitably used.

  Among these, in the method (i), when the adhesive layer contains a thermoplastic polyimide, the thermoplastic polyimide may have low solubility in an organic solvent. As a result, it may be difficult to provide the adhesive layer on the polyimide film. Therefore, in order to avoid the above problem, it is more preferable to prepare a solution containing polyamic acid which is a precursor of thermoplastic polyimide, apply it to a polyimide film, and then imidize it. As the imidization method at this time, either a thermal imidization method or a chemical imidization method may be used. However, when the chemical imidization method is used, it may be necessary to set heating conditions for removing the dehydrating agent and the like without thermally deteriorating the adhesive layer. Therefore, in this case, it is more preferable to imidize by a thermal imidization method.

  The higher the temperature at the time of thermal imidation, the faster the imidization rate, that is, imidization is likely to occur. However, if the imidization temperature is too high, the thermoplastic polyimide may undergo thermal decomposition. On the other hand, if the temperature at the time of thermal imidization is too low, imidization is difficult to proceed, and the time required for the imidization step becomes long.

  Therefore, from the viewpoint of productivity, the temperature at the time of thermal imidization is preferably set within the range of glass transition temperature to glass transition temperature + 200 ° C. of the thermoplastic polyimide, glass transition temperature + 50 ° C. to glass transition temperature + 150 ° C. It is more preferable to set within the range.

  Further, the imidization time is not uniquely limited, and it is sufficient to take a sufficient time for the imidization and drying to be substantially completed. Generally, it is appropriately set within a range of about 1 to 600 seconds.

  Further, for the purpose of improving the melt fluidity of the adhesive layer, it is possible to intentionally “lower the imidization rate” and / or “remain the solvent”.

  Moreover, what is necessary is just to adjust suitably about the thickness structure of a contact bonding layer and a polyimide film so that it may become the total thickness according to a use. Moreover, you may perform various surface treatments, such as a corona treatment, a plasma treatment, a coupling process, on the polyimide film surface before providing an adhesive layer as needed.

  In the flexible metal-clad laminate according to the present invention, the method (i) or (ii), particularly the method (ii), may be used for bonding the metal foil and the polyimide film through the adhesive layer. preferable. Specifically, a laminating method using a continuous process using a hot roll laminator having a pair of metal rolls can be used. When a hot roll laminating apparatus having a pair of metal rolls is used, lamination is performed at a high temperature. Moreover, since the heating roll with which a hot roll laminating apparatus is equipped and a laminated material are line-contacted, a pressure is applied locally to a laminated material. In particular, when the thickness of the film-like joining member is thin, it is difficult to uniformly apply pressure to the material to be laminated at the time of lamination. ADVANTAGE OF THE INVENTION According to this invention, the dimensional change which generate | occur | produces when manufacturing a flexible metal-clad laminated board using a hot roll laminating apparatus can be suppressed effectively.

  More specifically, the method for producing a flexible metal-clad laminate according to the present invention includes (1) using a hot roll laminator having a pair of metal rolls on one or both sides of a metal foil and a polyimide film. A step of thermally laminating and bonding a film-like joining member having a total thickness of 5 to 15 μm on which an adhesive layer containing thermoplastic polyimide is formed, and (2) prior to the step (1), the film-like joining. And pressing the arcuate shaft having a large number of rotating bodies against the member.

  In the step (1), the heating method of the material to be laminated at the time of heat lamination (step of heat lamination) is not particularly limited. For example, it is possible to use a heating means employing a conventionally known method that can heat at a predetermined temperature, such as a heat circulation method, a hot air heating method, an induction heating method, or the like. Similarly, the method for pressurizing the material to be laminated at the time of thermal lamination is not particularly limited. For example, it is possible to use a pressurizing means that employs a conventionally known method that can apply a predetermined pressure, such as a hydraulic method, a pneumatic method, or a gap pressure method.

  The heating temperature at the time of thermal lamination (hereinafter also referred to as “laminating temperature”) is preferably a glass transition temperature (Tg) of the film-like joining member + 50 ° C. or more, and more preferably Tg + 100 ° C. or more of the film-like joining member. preferable. If it is Tg + 50 degreeC or more temperature, a film-like joining member and metal foil can be heat-laminated favorably. Moreover, if it is Tg + 100 degreeC or more, the lamination speed can be raised and the productivity of a flexible metal-clad laminated board can be improved more. In general, the laminating temperature is preferably 300 ° C to 500 ° C. When the laminating temperature is 300 ° C. or higher, the effect of the present invention appears particularly remarkably, and a flexible metal-clad laminate having excellent dimensional stability can be produced. Moreover, if it is 500 degrees C or less, deterioration of a material can be prevented.

  The laminating speed during thermal lamination is preferably 0.5 to 10 m / min, more preferably 1.0 to 10 m / min. If it is 0.5 m / min or more, sufficient thermal lamination is possible, and if it is 1.0 m / min or more, productivity can be further improved.

  Furthermore, the higher the pressure at the time of thermal lamination, that is, the lamination pressure, there is an advantage that the lamination temperature can be lowered and the lamination speed can be increased. However, generally, when the laminating pressure is too high, the dimensional change of the obtained laminate tends to deteriorate. On the other hand, when the lamination pressure is too low, the adhesive strength of the metal foil of the resulting laminate is reduced. Therefore, the laminating pressure is preferably in the range of 49 to 490 N / cm 2 (5 to 50 kgf / cm 2), and more preferably in the range of 98 to 294 N / cm 2 (10 to 30 kgf / cm 2). Within this range, the three conditions of laminating temperature, laminating speed, and laminating pressure can be improved, and productivity can be further improved.

  In the present invention, it is preferable that the tension applied to the film-like joining member at the time of heat laminating is in a specific range, thereby changing the dimensional change of the obtained flexible metal-clad laminate, particularly when heated after removing the metal foil. It becomes possible to suppress. Specifically, it is in the range of 0.01 to 1 N / cm, preferably in the range of 0.1 to 1 N / cm, and more preferably in the range of 0.3 to 1 N / cm. In order to ensure the transportability of the film, it is difficult to reduce the tension applied to the film-like joining member during thermal lamination, and this method is not a means usually employed. It has been found that dimensional changes can be suppressed by reducing the tension applied to the joining member. In addition, the tension | tensile_strength concerning a film-like joining member means the tension | tensile_strength concerning a film-like joining member just before entering a laminate roll, and can be detected with a tension pick-up roll.

  In the present invention, before the step of heat laminating (the above step (1)), the step of bringing the arcuate shaft having one or more rotating bodies into contact with the film-like joining member (the above step (2)) ) Is preferably included.

The present inventors secure transportability and suppress dimensional change by performing the step of bringing the arcuate shaft having one or more rotating bodies into contact with the film-like coupling member prior to the heat laminating step. In addition, the present inventors have found that a metal-clad laminate having an excellent appearance can be obtained. It is preferable to install the arcuate shaft having one or more rotating bodies as close as possible to the thermal laminating roll as much as possible in terms of apparatus, and preferably within 1.5 m immediately before the thermal laminating roll, It is preferable to install within 1.0 m. Most preferably, it should be installed within 0.5 m immediately before thermal lamination. Preferably pressing the arcuate rod into a film coupling member, it is preferable pressure is pressed against the arcuate rod is 0.1g~50g / cm ^2. If the pressure applied is too large, the film is locally tensioned and the dimensional change rate may deteriorate.

  An arcuate shaft having a large number of rotating bodies is divided into a method in which an arc is vertically pressed from the top or bottom of the film and a method in which the arc is horizontally aligned. A metal-clad laminate with excellent appearance can be obtained by pressing the film vertically from the top or bottom of the film, but when the dimensional change rate varies due to the difference in pressure between the arcuate bars at the center and end of the film. There is. Therefore, a method of pressing the arcuate bar horizontally is preferable. The shape of the arcuate bar may be changed depending on the joining member to be used, but an arcuate bar having a gentle curve is preferable.

  The shape, size, material, and the like of the rotating body can take an optimum form depending on the joining member to be thermally laminated. The shape is such that it has a frictional property that does not damage the film surface and does not have an edge. Further, in order to eliminate sagging and undulations, it is desirable that the rotating body and the film ground contact portion be flat. The size of the rotating body is desirably the minimum size that can eliminate sagging, undulations, and the like, and it is preferable that the interval between the rotating bodies is small. As in the previous description, the material preferably has a frictional property that does not damage the film surface and has an optimal elastic modulus and hardness. The material can be selected according to the joining member used. In addition, this rotating body has a configuration in which all rotating bodies are arranged in parallel with the flow direction of the joining member (FIG. 2), and the rotating body opens in a U shape outward from the center of the joining member (FIG. 3). ) Is more effective.

  Further, in the present invention, the specific configuration of the means for carrying out the thermal lamination is not particularly limited, but in order to improve the appearance of the resulting laminate, the space between the pressing surface and the metal foil is not limited. It is preferable to arrange a protective film.

  The protective film may be any film that can withstand the heating temperature during thermal lamination, and examples thereof include heat-resistant plastics such as non-thermoplastic polyimide films, copper foils, aluminum foils, and metal foils such as SUS foils. It is done. Among these, a non-thermoplastic polyimide film can be suitably used from the viewpoint of excellent balance between heat resistance and reusability.

  Moreover, when the thickness of the protective film is thin, the role of buffering and protection during lamination cannot be sufficiently achieved. Therefore, when a non-thermoplastic polyimide film is used as the protective film, the thickness is preferably 75 μm or more.

  The protective film is not necessarily a single layer, and may have a multilayer structure of two or more layers having different characteristics.

  Further, since the adhesive layer contains thermoplastic polyimide, the lamination temperature becomes very high. Therefore, if the protective film is used as it is for the laminate, the appearance and dimensional stability of the resulting flexible metal-clad laminate may be deteriorated due to rapid thermal expansion. Therefore, it is preferable to preheat the protective film before lamination.

  Examples of the preheating means include a method in which the protective film is brought into contact with a heat roll. Whichever method is employed, it is preferable that the surface temperature of the protective film is within the range of “the surface temperature of the hot roll−10 ° C. to the surface temperature of the hot roll” during lamination. Here, the “surface temperature of the protective film” refers to the temperature of the surface in contact with the metal foil during lamination.

  By setting the surface temperature of the protective film within the above range, since the thermal expansion of the protective film is completed at the time of lamination, it is possible to suppress the appearance and dimensional change of the flexible metal-clad laminate. If the surface temperature of the protective film deviates from the above range, lamination is performed without completing the thermal expansion of the protective film, so rapid thermal expansion occurs during lamination, and the appearance and dimensional changes of the resulting laminate may deteriorate. There is sex.

  The distance and time for holding the protective film on the hot roll are not particularly limited, and may be appropriately adjusted from the thickness of the protective film, the diameter of the hot roll, the lamination speed, and the like. About the surface temperature of a protective film and a heat roll, it can measure by well-known methods, such as a contact-type thermometer and a thermocouple.

  Moreover, it is preferable that the tension | tensile_strength concerning the said protective film in the range of 600-2000 N / m at the time of a thermal lamination. By setting it as the said structure, generation | occurrence | production of the sagging of a protective film, wrinkles, etc. can be suppressed, without cut | disconnecting a film. Therefore, there is an effect that a metal-clad laminate having a good appearance can be obtained.

<V. Manufacturing equipment for flexible metal-clad laminates>
In order to obtain the flexible metal-clad laminate according to the present invention, a hot roll laminating apparatus having a pair of metal rolls or a continuous treatment by a double belt press (DBP) can be used. Especially, it is preferable to use the hot roll laminating apparatus which has a pair or more metal roll from the point that an apparatus structure is simple and it is advantageous at the surface of a maintenance cost. In the above-mentioned hot roll laminating apparatus, the material to be laminated can be pressure-bonded while being continuously heated.

  The “heat roll laminating apparatus having a pair of metal rolls” herein may be an apparatus having a metal roll for heating and pressurizing a material, and the specific apparatus configuration is particularly limited. It is not a thing.

  Furthermore, the above-mentioned heat laminating apparatus may be provided with a material to be laminated material feeding means for feeding the material to be laminated before the heat laminating means. Further, a layered material winding unit for winding the layered material may be provided after the thermal laminating unit. By providing these means, the productivity of the thermal laminating apparatus can be further improved.

  The specific configurations of the laminated material feeding means and the laminated material winding means are not particularly limited. For example, a film-like joining member, a metal foil, or a known laminated plate can be taken up. And a roll winder.

  Furthermore, it is more preferable to provide a protective film winding means or a protective film feeding means for winding or feeding the protective film. If these protective film winding means and protective film feeding means are provided, the protective film can be reused by winding the protective film once used in the heat laminating step and installing it again on the feeding side. .

  Moreover, when winding up a protective film, in order to align the both ends of a protective film, you may provide an edge part position detection means and a winding position correction means. Thereby, since the edge part of a protective film can be aligned and wound accurately, the efficiency of reuse can be improved. Specific configurations of the protective film winding means, the protective film feeding means, the end position detecting means, and the winding position correcting means are not particularly limited, and various conventionally known devices can be used.

  Note that the present invention is not limited to the configurations described above, and various modifications are possible within the scope of the claims, and technical means disclosed in different embodiments are appropriately combined. Embodiments obtained in this manner are also included in the technical scope of the present invention.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited only to these Examples. Those skilled in the art can make various changes, modifications, and alterations without departing from the scope of the present invention. In addition, the glass transition temperature of the thermoplastic polyimide in the synthesis examples, examples, comparative examples, and reference examples, the dimensional change rate during heating of the film-like joining member, the dimensional change rate of the flexible metal-clad laminate, and the metal foil peel strength The evaluation method is as follows.

[Glass transition temperature of thermoplastic polyimide]
The glass transition temperature was measured with a DMS200 manufactured by Seiko Instruments Inc. at a temperature rising rate of 3 ° C./min in a temperature range from room temperature to 400 ° C., and the inflection point of the storage elastic modulus was taken as the glass transition temperature.

[Dimensional change rate of flexible metal-clad laminate]
Based on JIS C6481, an etching process is carried out on a flexible metal-clad laminate, and after removing the metal foil from the flexible metal-clad laminate, four holes are formed, and a constant temperature room at 20 ° C. and 60% RH is formed. After being left for 24 hours, the distance of each hole was measured. This distance was set to D1.

  Then, after heating at 250 ° C. for 30 minutes, it was left in a constant temperature room at 20 ° C. and 60% RH for 24 hours. Then, each distance was measured about the said four holes. The measured value of the distance of each hole after heating was set to D2, and the dimensional change rate before and after heating was calculated by the following formula.

Dimensional change rate (%) = {(D2-D1) / D1} × 100
In addition, the said dimensional change rate was measured about both MD direction and TD direction.

[Stripping strength of metal foil: Adhesive strength]
A sample was prepared according to “6.5 Peel Strength” of JIS C6471, and a 5 mm wide metal foil part was peeled off at a peeling angle of 180 degrees and 50 mm / min, and the load was measured.

[Appearance of flexible metal-clad laminate]
The appearance of the flexible metal-clad laminate after lamination and the appearance defects such as wrinkles after removing the copper foil were visually confirmed. Further, when detailed confirmation is necessary, confirmation by an optical microscope was performed at the judgment of a person skilled in the art.

[Measurement of tension applied to protective material]
A tension pick-up roll was provided in front of the laminate roll, and the tension was detected. This was used as the tension applied during lamination.

[Synthesis Example 1; Synthesis of polyimide film]
Pyromellitic dianhydride / p-phenylenebis (trimellitic acid monoester acid anhydride) / 4,4′-diaminodiphenyl ether / paraphenylenediamine in a molar ratio of 1/1/1/1 respectively. , N′-dimethylacetamide was polymerized in a solvent so that the solid content was 18% by weight.

  The polymerization solution was cooled to about 0 ° C., and 2.1 mol% acetic anhydride and 1.1 mol% isoquinoline were added to 1 mol of amic acid in the polyamic acid solution cooled to about 0 ° C. After sufficiently stirring, the mixture was extruded from a die maintained at about 5 ° C. and cast onto an endless belt. A gel film having a gel afterglow of 54% was obtained by heating at 140 ° C. or lower on an endless belt.

  The self-supporting green sheet (gel film) is peeled off, and then both ends of the sheet are fixed to a pin sheet that continuously conveys the sheet, and conveyed to a heating furnace at 200 ° C. for 1 minute, 300 ° C. , 1 minute, 400 ° C., 1 minute, 500 ° C., 2 minutes, the film was peeled off from the pin, and wound to obtain a 1.2 m-wide polyimide film (thickness 10 μm).

[Synthesis Example 2; Synthesis of thermoplastic polyimide precursor]
780 g of DMF and 115.6 g of 2,2-bis [4- (4-aminophenoxy) phenyl] propane (hereinafter also referred to as “BAPP”) were added to a glass flask having a volume of 2000 ml, and the mixture was stirred under a nitrogen atmosphere. 3,3′4,4′-biphenyltetracarboxylic dianhydride (hereinafter also referred to as “BPDA”) was gradually added. Subsequently, 3.8 g of ethylene bis (trimellitic acid monoester acid anhydride) (hereinafter also referred to as “TMEG”) was added and stirred for 30 minutes in an ice bath. A solution prepared by dissolving 2.0 g of TMEG in 20 g of N, N-dimethylformamide (hereinafter also referred to as “DMF”) was prepared separately, and this was gradually added to the above reaction solution while paying attention to viscosity. Stirring was performed. When the viscosity reached 3000 poise (300 Pa · s), the addition and stirring were stopped to obtain a polyamic acid solution.

  This polyamic acid solution was cast on a 25 μm PET film (Therapy HP, manufactured by Toyo Metallizing Co., Ltd.) so as to have a final thickness of 20 μm, and dried at 120 ° C. for 5 minutes. After the dried self-supporting film is peeled off from PET, it is fixed to a metal pin frame and dried at 150 ° C. for 5 minutes, 200 ° C. for 5 minutes, 250 ° C. for 5 minutes, and 350 ° C. for 5 minutes. A single layer sheet was obtained. The glass transition temperature of this thermoplastic polyimide was 240 ° C.

[Example 1: Production of flexible metal-clad laminate]
After diluting the polyamic acid solution obtained in Synthesis Example 2 with DMF until the solid content concentration becomes 10% by weight, the final thermoplastic polyimide layer (adhesive layer) is formed on both sides of the polyimide film (10 μm thickness) of Synthesis Example 1 After applying the polyamic acid so that the typical thickness of one side was 2 μm, heating was performed at 140 ° C. for 1 minute. Subsequently, heat imidization was performed by passing through a far infrared heater furnace having an atmospheric temperature of 390 ° C. for 20 seconds to obtain a heat-resistant adhesive film (film-like joining member). 18 μm rolled copper foil (BHY-22B-T, manufactured by Japan Energy Co., Ltd.) on both sides of the obtained adhesive film (film-like joining member), and Apical 125 NPI (manufactured by Kaneka Co., Ltd.) on both sides of the copper foil as protective films As shown in FIG. 2, an arcuate shaft having a plurality of rotating bodies is installed at a pressure of 50 g / cm ² , the tension of the adhesive film (film-like joining member) is 0.1 N / cm, and the protective film tension Thermal lamination was performed continuously under the conditions of 300 N / cm, laminating temperature 380 ° C., laminating pressure 196 N / cm 2 (20 kgf / cm 2), laminating speed 1.5 m / min, and a flexible metal-clad laminate was produced. Table 1 shows the characteristics of the flexible metal-clad laminate.

[Example 2: Production of flexible metal-clad laminate]
3 except that an arcuate shaft having a plurality of rotating bodies was installed at a pressure of 0.1 g / cm ² and the tension of the adhesive film (film-like joining member) was 0.02 N / cm as shown in FIG. In the same manner as in Example 1, a flexible metal-clad laminate was produced.

[Comparative Example 1: Production of flexible metal-clad laminate]
A flexible metal-clad laminate was produced in the same manner as in Example 1 except that the arcuate shaft having a large number of rotating bodies was not installed and the tension of the adhesive film (film-like joining member) was 0.4 N / cm.

  In Examples 1 and 2, which had a step of pressing an arcuate shaft having a large number of rotating bodies before the laminating step, and the tension of the film-like joining member was controlled within an appropriate range, good dimensional stability was obtained, The appearance and the appearance after etching were also good.

  Note that the present invention is not limited to the configurations described above, and various modifications are possible within the scope of the claims, and technical means disclosed in different embodiments and examples respectively. Embodiments and examples obtained by appropriately combining them are also included in the technical scope of the present invention.

  As described above, the flexible metal-clad laminate of the present invention effectively suppresses dimensional changes even when the thickness is thin, as in a half mill product. Therefore, it can be suitably used for an FPC or the like that requires foldability, bending resistance and fine wiring, and problems such as misalignment during component mounting can be improved. Therefore, the present invention can be used not only in the field of producing various resin molded products typified by a laminate composed of a polyimide adhesive film (film-like joining member), but also from such an adhesive film. The present invention can also be widely applied to fields related to the manufacture of electronic components using the laminated body.

It is a figure which shows an example of the heat roll laminating apparatus which installed the arcuate axis | shaft which has a some rotary body before this heat laminating roll. The figure which shows an example of the arcuate axis | shaft which has two or more rotary bodies arranged in parallel with the advancing direction of a film-form joining member The figure which shows an example of the arcuate axis | shaft which has two or more rotating bodies located in a line from the center of the film-shaped joining member.

Claims (4)

(1) Using a hot roll laminator having a pair of metal rolls, a film having a total thickness of 5 to 15 μm in which an adhesive layer containing thermoplastic polyimide is formed on one side or both sides of a metal foil and a polyimide film. The bonding member and the step of heat laminating and bonding the tension applied to the film-shaped bonding member within the range of 0.01 to 1 N / cm,
(2) A method for producing a flexible metal-clad laminate comprising the step of bringing an arcuate shaft having one or more rotating bodies into contact with the film-like joining member prior to the step (1). 2. The production of a flexible metal-clad laminate according to claim 1, wherein in the step (1), a protective film is used and heat-lamination is performed with a tension applied to the protective film in a range of 600 to 2000 N / m. Method. Before the protective film is subjected to thermal lamination, the protective film is brought into contact with a thermal roll, so that the surface temperature of the protective film at the time of thermal lamination is the surface temperature of the thermal roll of −10 ° C. to the surface temperature of the thermal roll. The method for producing a flexible metal-clad laminate according to claim 1, further comprising a step of heat laminating within the range. The method for producing a flexible metal-clad laminate according to any one of claims 1 to 3, wherein a heating temperature at the time of thermal lamination is 300 ° C to 500 ° C.

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