JP2016049773A - Three-layer flexible metal-clad laminate and double-sided three-layer flexible metal-clad laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-layer flexible metal-clad laminate and a double-sided three-layer flexible metal-clad laminate, in which sufficient adhesive performance is maintained even when thickness of an adhesive layer in the three-layer flexible metal-clad laminate is extremely thin.SOLUTION: A three-layer flexible metal-clad laminate includes a metal layer 11, an adhesive layer 12, and a resin layer 13. In the three-layer flexible metal-clad laminate, the surface of the metal layer 11 laminated on the adhesive layer 12 formed on the main surface of the resin layer 13 has 10-point average roughness (Rz) of 0.05-0.25 μm and the surface area rate of 1.0001-1.010, and the adhesive layer has thickness of 0.3-3.0 μm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a three-layer flexible metal-clad laminate and a double-sided three-layer flexible metal-clad laminate.

  The flexible metal laminate is widely used in the field of electronic materials, and is a two-layer flexible metal-clad laminate comprising a metal layer and a polyimide layer, and a three-layer flexible metal laminate comprising a metal layer, a polyimide layer and an adhesive layer. It has been known.

  By the way, with the recent thinning and miniaturization of electronic devices, in the field of flexible metal-clad laminates, the thickness of each layer of the flexible metal-clad laminate is made as thin as possible and a higher definition wiring pattern is formed. Therefore, there is a tendency to use a low profile copper foil. On the other hand, it is known that the adhesiveness decreases when the thickness of the adhesive layer is reduced. Moreover, the low profile copper foil has a feature that the anchor effect is difficult to obtain because the surface roughness of the copper foil is small.

Patent Document 1 discloses a flexible printed circuit board having a three-layer structure in which the thickness of an adhesive layer is 0.5 to 25 μm.
In Patent Document 2, the surface roughness (Rz) of the copper foil is made as small as possible, the surface shape of the copper foil is made a complicated surface shape, and both high-definition of the wiring pattern and adhesion to the substrate are compatible. The illustrated copper foil and a laminate using the copper foil are disclosed.

JP 2006-165495 A JP 2013-77702 A

  However, in the flexible printed board disclosed in Patent Document 1, when the thickness of the adhesive layer is 2 μm or less, there is a possibility that sufficient adhesiveness may not be exhibited.

  Moreover, when the copper foil disclosed by patent document 2 is used for the metal layer of a three-layer flexible metal-clad laminated board, there exists a possibility that sufficient adhesiveness may not be expressed when the thickness of an adhesive bond layer will be 2 micrometers or less.

  The present invention relates to a flexible metal-clad laminate, particularly a three-layer flexible metal-clad laminate and a double-sided three-layer that can maintain sufficient adhesion even when the thickness of the adhesive layer in the three-layer flexible metal-clad laminate is extremely thin. An object is to provide a flexible metal-clad laminate.

  In order to solve the above-mentioned problem, in the first aspect of the present invention, a three-layer flexible metal-clad laminate including a metal layer, an adhesive layer, and a resin layer, the main surface of the resin layer being The 10-point average roughness (Rz) of the surface on the adhesive layer side of the metal layer laminated on the formed adhesive layer is 0.05 to 0.25 μm, and the surface area ratio is 1.0001 to 1.010. The thickness of the adhesive layer is 0.3 to 3.0 μm.

  In the second aspect of the present invention, a resin layer having a first main surface and a second main surface, and a first adhesive layer and a first metal layer in this order on the first main surface. A double-sided three-layer flexible metal-clad laminate in which a second adhesive layer and a second metal layer are laminated in this order on the second main surface, wherein the first metal layer has the first metal layer. 10-point average roughness (Rz) of the surface of the second metal layer and the surface of the second metal layer on the second adhesive layer side is 0.05 to 0.25 μm, and the surface area ratio is 1.0001 to 1. 010, and the thickness of the first adhesive layer and the second adhesive layer is 0.3 to 3.0 μm.

  It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

1 is a schematic cross-sectional view of a three-layer flexible metal-clad laminate according to an embodiment. It is a schematic sectional drawing of the double-sided three-layer flexible metal-clad laminate concerning an embodiment. It is an expansion schematic sectional drawing of a 3 layer flexible metal laminated board.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention. In the drawings, positional relationships such as up, down, left and right are based on the positional relationships shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios. Further, in the drawings, overlapping description of common elements is omitted.

(3-layer flexible metal-clad laminate)
FIG. 1 is a schematic cross-sectional view of a three-layer flexible metal-clad laminate according to this embodiment. The three-layer flexible metal-clad laminate 10 includes a resin layer 13, an adhesive layer 12 formed on the surface (main surface) of the resin layer 13, and a metal layer 11 adhered to the resin layer 13 via the adhesive layer 12. Are three-layer flexible metal-clad laminates.

  It is preferable that the surface of the metal layer 11 to be bonded to the adhesive layer 12 is as smooth as possible. Smoothness here means that both the 10-point average roughness (Rz) and the surface area ratio (S ratio) of the surface of the metal layer 11 are small. Specifically, from the viewpoint of adhesion between the metal layer 11 and the adhesive layer 12, the surface of the metal layer 11 has a 10-point average roughness (Rz) in the range of 0.05 to 0.25 μm, and the surface The surface area ratio (S ratio) is preferably in the range of 1.0001 to 1.010, Rz is in the range of 0.05 to 0.20 μm, and S ratio is in the range of 1.0001 to 1.005. More preferably. If the upper limit of the 10-point average roughness (Rz) and the surface area ratio (S ratio) is exceeded, the thickness of the adhesive layer 12 cannot be reduced. Thereby, for example, the influence on flame retardancy, solder heat resistance, dimensional stability, and the like is increased. When the value is less than the lower limit, the surface of the metal layer 11 is in a mirror state, but this is not practically present. In addition, 10-point average roughness (Rz) and a surface area ratio (S ratio) can be measured by the method as described in the Example mentioned later.

  The material of the metal layer 11 is not particularly limited, and various metals can be used. For example, copper, aluminum, stainless steel, etc. are mentioned. Among these, it is preferable that the metal layer 11 is a copper foil layer from the viewpoint of improving functionality as a flexible metal-clad laminate and forming a circuit. Moreover, although copper foil has electrolytic copper foil and rolled copper foil, when manufacturing copper foil, electrolytic copper foil is preferable from the few dents formed on the surface of copper foil.

  The thickness of the metal layer 11 is not specifically limited, A suitable thickness can be selected suitably. In this embodiment, it is preferable that it is 3-35 micrometers from a viewpoint of workability.

  The adhesive layer 12 can be appropriately selected using a thermoplastic polyimide resin, an epoxy resin, an acrylic resin, a urethane resin, or a polyester resin as a main ingredient. Depending on the characteristics required for the flexible metal-clad laminate, two or more kinds of resins may be selected and combined. Moreover, a hardening | curing agent, a hardening accelerator, and another additive can be added to a main ingredient, and it can be set as a resin composition. Among these, it is preferable to use a thermoplastic polyimide resin composition and an epoxy resin composition from the viewpoints of heat resistance and flame retardancy.

  As the thermoplastic polyimide resin, those obtained by using at least one tetracarboxylic dianhydride and one or more diamines as raw materials are shown. Here, the term “thermoplastic” means that it has a glass transition temperature in the range of 100 ° C. to 400 ° C., melts and flows by heating at a temperature equal to or higher than the glass transition temperature, and can be molded.

  The tetracarboxylic dianhydride and diamine used as raw materials are not particularly limited as long as they have thermoplasticity, and known raw materials can be used.

  The tetracarboxylic dianhydride as a raw material includes 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2, 3,6,7-naphthalenetetracarboxylic dianhydride, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl Ether tetracarboxylic dianhydride, p-phenylenebis (trimellitic acid monoester acid anhydride), m-phenylenebis (trimellitic acid monoester acid anhydride), o-phenylenebis (trimellitic acid monoester acid anhydride) Product), TABP, p-methylphenylenebis (trimellitic acid monoester anhydride), 3,3 ′, 4,4′-biphenylsulfonetetracarboxylic dianhydride 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropanoic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propanoic dianhydride, 1,4,5,8- Naphthalenetetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 5- (dioxotetrahydrofuryl-3-methyl-3) -Cyclohexene-1,2-dicarboxylic dianhydride, 4- (2,5-dioxotetrahydrofuran-3-yl) -tetralin-1,2-dicarboxylic dianhydride, tetrahydrofuran-2,3,4,5 -Tetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, etc. Et a can be used in combination to select two or more types.

  Similarly, diamines include p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, 2,4-diaminoxylene, 2,4-diaminodurene, 4,4′-diamino. Diphenylmethane, 4,4′-methylenebis (2-methylaniline), 4,4′-methylenebis (2-ethylaniline), 4,4′-methylenebis (2,6-dimethylaniline), 4,4′-methylenebis ( 2,6-diethylaniline), 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 3,3′-diaminodiphenyl ether, 2,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfone, 3 , 3′-Diaminodiphenylsulfone, 4,4′-diaminobenzopheno 3,3′-diaminobenzophenone, 4,4′-diaminobenzanilide, benzidine, 3,3′-dihydroxybenzidine, 3,3′-dimethoxybenzidine, o-tolidine, m-tolidine, 2,2′-bis (Trifluoromethyl) benzidine, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 4,4 ′ -Bis (4-aminophenoxy) biphenyl, bis (4- (3-aminophenoxy) phenyl) sulfone, bis (4- (4-aminophenoxy) phenyl) sulfone, 2,2-bis (4- (4-amino) Phenoxy) phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane, 2,2 Bis (4-aminophenyl) hexafluoropropane, p-terphenylenediamine, 4,4′-methylenebis (cyclohexylamine), isophoronediamine, trans-1,4-diaminocyclohexane, cis-1,4-diaminocyclohexane, 1 , 4-cyclohexanebis (methylamine), 2,5-bis (aminomethyl) bicyclo [2.2.1] heptane, 2,6-bis (aminomethyl) bicyclo [2.2.1] heptane, 3, 8-bis (aminomethyl) tricyclo [5.2.1.0] decane, 1,3-diaminoadamantane, 2,2-bis (4-aminocyclohexyl) propane, 2,2-bis (4-aminocyclohexyl) Hexafluoropropane, 1,3-propanediamine, 1,4-tetramethylenediamine, 1,5-pe And n-amethylenediamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, and 1,9-nonamethylenediamine. Two or more of these can be selected and used in combination.

  When a thermoplastic polyimide resin is used for the adhesive layer 12, the thermoplastic polyimide precursor dissolved in a solvent is applied to the metal layer 11 or the resin layer 13, dried, and an imidization reaction is performed as necessary. The adhesive layer 12 made of a thermoplastic polyimide resin can be obtained.

  Known methods can be applied to the method of polymerizing the thermoplastic polyimide precursor and the imidization reaction of the precursor. The timing for polymerizing the precursor is preferably performed before being applied to the metal layer 11 or the resin layer 13. The imidation reaction of the precursor is preferably performed after the precursor is applied to the metal layer 11 or the resin layer 12.

  The epoxy resin is not particularly limited. For example, bisphenol type epoxy resin such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, novolak type such as phenol novolac type epoxy resin, cresol novolac type epoxy resin, etc. Examples thereof include an epoxy resin, a biphenyl type epoxy resin, and a naphthalene ring-containing epoxy resin. From the viewpoint of heat resistance and flame retardancy, it is preferable to use a biphenyl type epoxy resin or a naphthalene ring-containing epoxy resin.

  As an acrylic resin, the polymer obtained by superposing | polymerizing monomers, such as (meth) acrylic-acid alkylester and (meth) acrylic acid, is shown.

  It does not specifically limit as a urethane resin, For example, what is obtained by polymerizing a polyester polyol and polyisocyanate is shown.

  The polyester resin is not particularly limited, and examples thereof include those obtained by polycondensation of dicarboxylic acid and polyalcohol.

  The curing agent is not particularly limited, and examples thereof include an epoxy resin, an isocyanate curing agent, and an imidazole curing agent. The compounding quantity of a hardening | curing agent is 0.5-50 weight part with respect to 100 weight part (solid content conversion) of the main ingredient resin which comprises an contact bonding layer, Preferably it is 5-20 weight part. Thereby, the electrical property requested | required of an electronic material can be satisfy | filled favorably.

  The isocyanate curing agent is not particularly limited, and examples thereof include isocyanate compounds such as TDI-TMP (tolylene diisocyanate-trimethylpropane adduct) and HMDI-TMP (hexamethylene diisocyanate-trimethylpropane adduct).

  The imidazole curing agent is not particularly limited, and examples thereof include imidazole compounds such as 2-methylimidazole and 2-methyl-4-methylimidazole.

  As other additives, rubber resins such as nitrile butadiene rubber and acrylic rubber may be added. The compounding amount (in terms of solid content) of the rubber-based resin is 10 to 200 parts by weight, preferably 50 to 100 parts by weight, relative to 100 parts by weight (in terms of solid content) of the main resin constituting the adhesive layer. Thereby, the flexibility required for the flexible printed wiring material can be satisfactorily satisfied.

  The thickness of the adhesive layer 12 is preferably 0.3 to 3.0 μm, more preferably 0.3 to less than 2.0 μm from the viewpoint of flame retardancy, and 0.3 to 1.5 μm or less. It is particularly preferred. When the thickness is 0.3 to 1.5 μm or less and the resin composition of the adhesive layer 12 is composed of an epoxy resin composition, an acrylic resin composition, a urethane resin composition, or a polyester resin composition, Addition of flame retardants such as halogen flame retardants and phosphorus flame retardants becomes unnecessary. When the thickness exceeds the upper limit value, the dimensional change rate at the time of circuit formation increases due to curing shrinkage or thermal expansion when the adhesive layer is cured. Moreover, when thickness becomes less than a lower limit, sufficient adhesiveness cannot be obtained.

  In the case where the resin composition of the adhesive layer 12 is composed of an epoxy resin composition, an acrylic resin composition, a urethane resin composition, or a polyester resin composition, the thickness of the adhesive layer 12 is 2.0 to 3.0 μm. In such a case, it is preferable to impart flame retardancy to the resin composition. Specifically, a flammable skeleton can be incorporated into a skeleton having a resin structure as a main component in the resin composition. For example, organic skeletons such as benzene, naphthalene and anthracene can be incorporated. Further, a halogen-based flame retardant or a phosphorus-based flame retardant may be added to the resin composition.

  The method for forming the adhesive layer 12 on the surface of the metal layer 11 or the resin layer 13 is not particularly limited, and various methods can be employed. For example, the resin composition diluted with a solvent can be applied to the metal layer 11 or the resin layer 13 by a known application method. Examples of the application means include a comma coater, a gravure coater, and a bar coater.

  As the solvent, for example, alcohol (for example, methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, cellsolve), ketone (for example, acetone, methyl ethyl ketone, cyclohexanone), aromatic hydrocarbon (for example, toluene, xylene), aliphatic Hydrocarbon (for example, hexane, octane, decane, dodencan), ester (for example, ethyl acetate, methyl propionate), ether (for example, tetrahydrofuran, ethyl butyl ether) and the like can be mentioned. These may be used alone or in combination of two or more.

  Examples of the material used for the resin layer 13 include polyethylene terephthalate, polyethylene naphthalate, polyimide, polyamide, liquid crystal polymer, syndiotactic polystyrene, polyphenylene sulfide, and the like. From the viewpoint of lowering the dielectric constant and dielectric loss tangent of the flexible metal-clad laminate, liquid crystal polymers, syndiotactic polystyrene and polyphenylene sulfide are preferred. A polyimide is preferable from the viewpoint of heat resistance and flame retardancy, and a polyimide containing silica is more preferable from the viewpoint of the smoothness and laminating properties of the resin layer surface. Further, the surface (main surface) of the resin layer 13 may be subjected to a plasma treatment or a corona treatment for increasing the surface activity from the viewpoint of expressing adhesiveness more strongly. Note that the term “laminate” refers to whether the metal layer and the resin layer are in close contact with each other through the adhesive layer. For example, when it adheres without a gap, it is evaluated that the laminating property is good.

  The thickness of the resin layer 13 is not particularly limited, and a suitable thickness can be selected as appropriate. From the viewpoint of thinning and miniaturization of the flexible metal-clad laminate, the thickness is preferably 5 to 25 μm, more preferably 4 to 15 μm.

  As a method for producing a three-layer flexible metal-clad laminate, for example, the resin composition according to the adhesive layer 12 diluted with a solvent is applied to the surface (main surface) of the resin layer 13 using a coater, and the resin composition Is cured to form a semi-cured state (B-stage state) to form the adhesive layer 12. Next, the adhesive layer 12 is bonded to the surface of the metal layer 11 having a predetermined 10-point average roughness and surface area ratio, and heated until the adhesive layer 12 is completely cured (C-stage state) (after baking). To do. Thereafter, it is cooled to room temperature to obtain a three-layer flexible metal-clad laminate 10.

(Double-sided three-layer flexible metal-clad laminate)
FIG. 2 is a schematic cross-sectional view of a double-sided three-layer flexible metal-clad laminate according to this embodiment. The double-sided three-layer flexible metal-clad laminate 200 includes a resin layer 210 having a first main surface and a second main surface, and a first adhesive layer 221 and a first metal layer on the first main surface. 231 are stacked in this order, and the second adhesive layer 222 and the second metal layer 232 are stacked in this order on the second main surface.

  As a method for producing a double-sided three-layer flexible metal-clad laminate, for example, the resin composition according to the adhesive layer 221 diluted with a solvent is applied to the first main surface of the resin layer 210 using a coater, and the above resin composition The product is cured so as to be in a semi-cured state (B stage state). Next, the resin composition related to the adhesive layer 222 diluted with a solvent is applied to the second main surface of the resin layer 210 using a coater so that the resin composition is in a semi-cured state (B stage state). Harden. In addition, you may apply | coat a resin composition to the said 1st main surface and the 2nd main surface simultaneously, and you may make it harden | cure simultaneously so that the said resin composition may be in a semi-hardened state (B stage state) after that. Thereafter, a metal layer 231 having a predetermined 10-point average roughness and surface area ratio is bonded to the adhesive layer 221 and a metal layer 232 having a predetermined 10-point average roughness and surface area ratio is simultaneously bonded to the adhesive layer 222. In addition, heating (after baking) is performed until the adhesive layers 221 and 222 are completely cured (C stage state). Thereafter, it is cooled to room temperature to obtain a three-layer flexible metal-clad laminate 200.

(Mechanism of adhesion)
Conventionally, in the field of flexible metal-clad laminates, the thinner the adhesive layer is, the smoother the surface of the adherend on which the adhesive layer is laminated and the lower the anchor effect, the less the adhesiveness can be expressed. It was known. However, in the present invention, it is possible to express the adhesiveness in a state where the conventional common sense is overturned and the surface of the metal layer on which the adhesive layer is laminated is smoothed and the thickness of the adhesive layer is reduced.

  At present, the detailed reason why this adhesiveness is developed is not clear, but the applicant speculates as follows.

  FIGS. 3A and 3B are enlarged schematic cross-sectional views of a three-layer flexible metal-clad laminate. FIG. 3B is a partially enlarged view of FIG. 3A for easy understanding. As shown in FIG. 3B, when the surface of the metal layer 11 is uneven, the thickness of the adhesive layer 12 existing between the resin layer 13 and the metal layer 11 depends on the shape of the surface of the metal layer 11. It becomes thicker (point a) or thinner (point b). Thereby, it is considered that the angle formed between the adherend (metal layer 11) and the adhesive layer 12 at the time of peeling is not constant, and the peeling force is not stable. On the other hand, when the surface of the metal layer 11 is smooth, the thickness of the adhesive layer 12 is less affected by the surface shape of the metal layer 11, so that the adhesive existing between the resin layer 13 and the metal layer 11 is present. The thickness of the layer 12 is uniform, and the angle formed between the metal layer 11 and the adhesive layer 12 at the time of peeling is also constant. As a result, it is presumed that the peeling interface becomes stable, the peeling force becomes constant, and the decrease in adhesiveness is suppressed. In addition, since the resin layer 13 is considerably smoother than the metal layer 11, it is considered that the degree that the surface of the resin layer 13 affects the adhesiveness is small.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited at all by the following Examples. In Examples and Comparative Examples, each physical property was measured and evaluated by the following methods.

(1) Surface roughness (10-point average roughness, Rz)
As the sample for measuring the surface roughness, the surface to be measured was washed with acetone and sufficiently dried. Next, the surface was measured under the following measurement conditions using a scanning probe microscope (Nanopics 2100 (Scanning probe microscope (SPM)) manufactured by Seiko Instruments Inc.), and based on the measurement data, according to JIS B0601 (2001), The surface roughness (10-point average roughness, Rz) was calculated.
Measurement mode Contact mode measurement area 100μm × 100μm
Scan speed 130SEC. / Frame

(2) Surface area ratio (S ratio)
The surface area ratio was calculated using analysis software dedicated to Nanopics 2100 based on data measured under the same conditions as the surface roughness. In addition, the surface area rate as used in the field of this invention means the ratio of the area when the designated area | region is assumed to be completely smooth, and the surface area of the said area | region produced with the surface shape of the target object.

(3) Peel strength (peel strength)
As a sample used for the peel strength (peel strength), a single-sided three-layer flexible copper-clad laminate described below was cut out to a width of 10 mm. The peel strength (peel strength) is a value measured under the following measurement conditions using EZ test (manufactured by Shimadzu Corporation).
Peeling speed 50mm / min
Peeling angle 180 ° pulling (copper foil drawing)

The peel strength (peel strength) was evaluated according to the following criteria.
◎ 7N / cm or more
○ ... 5 N / cm or more and less than 7 N / cm × ... less than 5 N / cm

(4) Combustion test A sample used in the combustion test was obtained by removing a copper foil of a double-sided three-layer flexible copper-clad laminate described later by etching with a ferric chloride solution, thoroughly washing with water, and then at 105 ° C for 30 minutes After drying and cooling to room temperature, it was cut into a size for UL testing. The combustion test was performed according to the UL94VTM test. Specifically, the above-described cylindrical sample was hung in the longitudinal direction, and the flame extinction time after 3 seconds of indirect flame was confirmed. Moreover, evaluation was evaluated according to the following evaluation criteria.
○ ... UL94VTM-0 equivalent
× ・ ・ ・ UL94VTM nonconformity

(5) Laminate test The sample used in the laminate test was prepared by removing the copper foil of a single-sided three-layer flexible copper-clad laminate described later by etching with a ferric chloride solution, washing thoroughly with water, and then washing at 30 ° C at 105 ° C. The sample was dried for 1 minute, cooled to room temperature, and then cut into a size of 10 cm × 10 cm. In the laminate test, this sample was observed at a magnification of 100 times using an optical microscope (manufactured by OLYMPUS, BX51), and evaluated according to the following criteria.
○: There are no voids and voids.
X: One or more voids and voids are confirmed.

(6) Solder heat resistance test The sample used in the solder heat resistance test was obtained by cutting a double-sided three-layer flexible copper-clad laminate described below into a size of 20 mm x 20 mm. In the solder heat resistance test, the sample was immersed in a 300 ° C. solder bath for 10 seconds, and then the appearance of the sample after pulling was visually confirmed. Evaluation was performed according to the following criteria.
○: No peeling or floating.
X: There are peeling and floating.

(Production of three-layer flexible copper-clad laminate)
(1) Preparation of resin composition (1-1) Non-flame retardant resin composition The resin composition is 100 parts by weight of bisphenol A type epoxy resin (AER6121 (75% dissolved product) manufactured by Asahi Kasei E-Materials Co., Ltd.) in terms of solid content. 8 parts by weight of diaminodiphenylsulfone, 0.5 part by weight of triethyl boron monoethylamine, 0.3 part by weight of imidazole (C11Z manufactured by Shikoku Kasei Co., Ltd.), acrylic rubber (S-VGLS-30 manufactured by Sakai Chemical Industry Co., Ltd.) (30% dissolved product) was added in an amount of 80 parts by weight in terms of solid content, 840 parts by weight of methyl ethyl ketone, and 10 parts by weight of propylene glycol monomethyl ether (Hisolv MP manufactured by Toho Chemical Industry Co., Ltd.). Got.

(1-2) Non-Flame Retardant Resin Composition The resin composition is 100 parts by weight of bisphenol A type epoxy resin (AER6121 (75% dissolved product) manufactured by Asahi Kasei E-Materials Co., Ltd.) and 8 parts by weight of diaminodiphenylsulfone. 0.5 parts by weight of boron trifluoride monoethylamine, 0.3 parts by weight of imidazole (C11Z manufactured by Shikoku Kasei Co., Ltd.), nitrile butadiene rubber (S-PNR-20 manufactured by Sakai Chemical Industry Co., Ltd. (20% dissolved product)) Was added in an amount of 50 parts by weight in terms of solid content, 700 parts by weight of methyl ethyl ketone, and 10 parts by weight of propylene glycol monomethyl ether (Hisolv MP manufactured by Toho Chemical Industry Co., Ltd.), and stirred well to obtain a resin composition.

(1-3) Non-Flame Retardant Resin Composition The resin composition is 100 parts by weight of bisphenol A type epoxy resin (AER6121 (75% dissolved product) manufactured by Asahi Kasei E-Materials Co.) and 8 parts by weight of diaminodiphenylsulfone. 0.5 parts by weight of boron trifluoride monoethylamine, 0.3 parts by weight of imidazole (C11Z manufactured by Shikoku Kasei Co., Ltd.), 100 parts by weight of phenoxy resin (PKHH manufactured by Inchem Co., Ltd.) in terms of solid content, and 700 parts by weight of methyl ethyl ketone 10 parts by weight of propylene glycol monomethyl ether (Hisolv MP manufactured by Toho Chemical Industry Co., Ltd.) were added and stirred well to obtain a resin composition.

(1-4) Flame Retardant Resin Composition The resin composition is a phosphorus-containing epoxy resin (FX-305EK70 (70% dissolved product) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) 90 parts by weight in terms of solid content, bisphenol A type epoxy 10 parts by weight of resin (AER260 manufactured by Asahi Kasei E-Materials Co., Ltd.), 12 parts by weight of diaminodiphenylsulfone, 0.5 parts by weight of boron trifluoride monoethylamine, and 0.2 parts by weight of imidazole (C11Z-CN, manufactured by Shikoku Kasei Co., Ltd.) Parts, 100 parts by weight of phenoxy resin (Mitsubishi Chemical YX-8100BH30 (30% dissolved product)) in terms of solid content, 300 parts by weight of methyl ethyl ketone, 350 weights of propylene glycol monomethyl ether (Hisolv MP, manufactured by Toho Chemical Industry Co., Ltd.) Was added and stirred well to obtain a resin composition.

(2) Production of single-sided, three-layer flexible copper-clad laminate (1-1) The resin composition obtained above was applied to a 12.5 μm polyimide film (Kapton EN (plasma-treated product) manufactured by Toray DuPont) and a bar coater. Was applied so that the film thickness after drying would be a predetermined film thickness, and dried at 100 to 150 ° C. for about 5 minutes using an oven (a thermostat PHH-101 manufactured by Espec Corp.). The film thickness after drying was measured using a high precision digital measuring instrument (LITEMATIC VL-50-B) manufactured by MITUTOYO.

Next, (1-1) A copper foil was bonded to the film surface coated with the resin composition using a roll laminator (First Laminator VA-700 manufactured by Taisei Laminator) under the following conditions.
Laminate roll temperature 30 ~ 150 ℃
Laminating speed 0.5-30m / min Laminating pressure (linear pressure) 0.1-5MPa

  Next, after baking, the sample was after-baked using an oven at 180 ° C. for 1 hour. Thereafter, the sample was cooled to room temperature to obtain a single-sided three-layer flexible copper-clad laminate.

(3) Double-sided three-layer flexible copper-clad laminate The double-sided three-layer flexible copper-clad laminate uses the above-mentioned (1-1) resin composition as a polyimide film and a bar coater, and the film thickness after drying is predetermined. The film is coated to a film thickness, dried using an oven at 100 to 150 ° C. for 5 minutes, and then dried using a bar coater on the polyimide surface to which the resin composition is not coated. It apply | coated so that thickness might become a predetermined | prescribed film thickness, and it dried on conditions of 100-150 degreeC and 5 minutes using oven. Then, copper foil was bonded together with the roll laminator simultaneously on both surfaces on the above-mentioned lamination conditions. Thereafter, after-baking was performed using an oven at 180 ° C. for 1 hour to obtain a double-sided three-layer flexible copper-clad laminate.

  Table 1 shows that the adhesive layer of the three-layer flexible copper-clad laminate is the above-mentioned (1-1) resin composition, the thickness after drying is 1.0 μm, and the resin layer has the same configuration of polyimide film 12.5 μm And the characteristic results in the respective examples and comparative examples in which the copper foil as the metal layer was appropriately changed.

(Example 1)
As the metal layer of the three-layer flexible metal-clad laminate, electrolytic copper foil T9DA SV (18 μm) manufactured by Fukuda Metal Foil Powder Co., Ltd. was used. The surface on which the adhesive layer is laminated is the M surface (mat surface).

(Example 2)
As the metal layer of the three-layer flexible metal-clad laminate, rolled copper foil GHSN HA (12 μm) manufactured by JX Nippon Mining & Metals was used. The surface on which the adhesive layer is laminated is the M surface (mat surface).

(Comparative Example 1)
As the metal layer of the three-layer flexible metal-clad laminate, rolled copper foil GHSN HA (12 μm) manufactured by JX Nippon Mining & Metals was used. The surface on which the adhesive layer is laminated is the S surface (glossy surface).

(Comparative Example 2)
As the metal layer of the three-layer flexible metal-clad laminate, electrolytic copper foil T4M DS HD (18 μm) manufactured by Fukuda Metal Foil Powder Co., Ltd. was used. The surface on which the adhesive layer is laminated is the M surface (mat surface).

(Comparative Example 3)
For the metal layer of the three-layer flexible metal-clad laminate, RCF T9DA (18 μm) of rolled copper foil manufactured by Fukuda Metal Foil Powder Co., Ltd. was used. The surface on which the adhesive layer is laminated is the M surface (mat surface).

(Comparative Example 4)
As the metal layer of the three-layer flexible metal-clad laminate, 3ECIII (18 μm) manufactured by Mitsui Kinzoku Co., Ltd. was used. The surface on which the adhesive layer is laminated is the M surface (mat surface).

  As is clear from Table 1, in Examples 1 and 2, sufficient characteristics were obtained in peel strength, laminating property and solder heat resistance. On the other hand, it can be seen that Comparative Example 1 to Comparative Example 4 do not have sufficient characteristics in terms of laminating properties and solder heat resistance. Among these, although the comparative example 1 and the comparative example 4 have expressed the peel strength of 5 N / cm or more, sufficient characteristic is not acquired by laminating property and solder heat resistance. This is probably because the surface of the copper foil on which the adhesive layer is laminated is not smooth and air exists between the adhesive layer and the copper foil layer. Furthermore, in Comparative Example 1 using the same rolled copper foil as in Example 2, the copper foil surface on which the adhesive layer is laminated uses the S surface (glossy surface). It is considered that sufficient characteristics could not be obtained because a recess called an oil pit formed during the production of the rolled copper foil was easily formed on the S surface, and air was easily present in the recess.

  Table 2 shows that the film layer of the three-layer flexible copper-clad laminate is polyimide film 12.5 μm made by Toray DuPont, the copper foil as the metal layer is T9DA SV foil 18 μm made by Fukuda Metal Foil Powder Co., Ltd., and the adhesive layer is It is a characteristic result in each Example and each comparative example which made the above-mentioned (1-1) resin composition, and changed the thickness after drying suitably. The adhesive layer was laminated on the M surface side (surface roughness 0.16 μm, surface area ratio 1.002) of the copper foil.

In Examples 3 to 8, sufficient properties were obtained in terms of laminating properties and peel strength. In particular, in Examples 3 to 6, since the thickness of the adhesive layer is less than 2 μm, a three-layer flexible metal tension equivalent to UL94VTM-0 is included even in a state where the resin composition of the adhesive layer does not contain a substance that exhibits flame retardancy. A laminate was obtained.
On the other hand, in Comparative Example 5, the thickness of the adhesive layer was 0.1 μm, which was insufficient as the thickness of the adhesive layer, so that sufficient characteristics were not obtained in terms of laminating properties and peel strength.

  In Table 3, the resin layer of the three-layer flexible copper-clad laminate has a polyimide film 12.5 μm configuration, the copper foil as the metal layer is T9DA SV foil 18 μm manufactured by Fukuda Metal Foil Powder Co., Ltd., and the adhesive layer is described above ( It is a resin composition (1-2)-(1-4) other than 1-1), Comprising: It is a characteristic result in each Example at the time of changing the thickness after drying between 0.7-3 micrometers. The adhesive layer was laminated on the M surface side (surface roughness 0.16 μm, surface area ratio 1.002) of the copper foil.

  In Examples 9 to 19, sufficient properties were obtained in terms of laminating properties and peel strength. In particular, in Examples 9, 10, 13 and 14, since the thickness of the adhesive layer is less than 2 μm, even in a state where the resin composition of the adhesive layer does not contain a substance exhibiting flame retardancy, 3 equivalent to UL94VTM-0. A layered flexible metal-clad laminate could be obtained.

  When the resin composition of the adhesive layer is made flame retardant, that is, Examples 17, 18 and 19 exhibit sufficient properties in laminating properties and peel strength, and even when the thickness is larger than 2 μm, UL94VTM It exhibited flame resistance equivalent to −0.

  Here, when the thickness of the adhesive layer is greater than 3 μm regardless of the presence or absence of flame retardancy of the resin composition as in Comparative Example 6, although not shown in Table 3, the dimensional stability of the three-layer flexible copper-clad laminate is not shown. Decreased. This is considered to be because the laminated board is easily affected by the curing shrinkage of the resin due to the increase in the thickness of the adhesive layer.

  The dimensional stability was evaluated by measuring the dimensional change rate. The dimensional change rate was measured by preparing a measurement sample in accordance with JIS C 6471 and using a manual type two-dimensional measuring machine bestol KANON Y-450 manufactured by Nakamura Seisakusho.

  As described above, the present invention has been described using the single-sided three-layer flexible copper-clad laminate, but also in the double-sided three-layer flexible copper-clad laminate that is another embodiment, the single-sided three-layer flexible copper-clad laminate It was confirmed that the same results were obtained.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  The order of execution of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior to”. It should be noted that the output can be realized in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for convenience, it means that it is essential to carry out in this order. It is not a thing.

10 three-layer flexible metal-clad laminate, 11 metal layers, 12 adhesive layers, 13 resin layers, 200 double-sided three-layer flexible metal-clad laminates, 210 resin layers, 221 adhesive layers, 222 adhesive layers, 231 metal layers, 232 metal layers .

Claims (14)

A three-layer flexible metal-clad laminate including a metal layer, an adhesive layer, and a resin layer,
The 10-point average roughness (Rz) of the surface on the adhesive layer side of the metal layer laminated on the adhesive layer formed on the main surface of the resin layer is 0.05 to 0.25 μm, and the surface area ratio is 1.0001 to 1.010,
A three-layer flexible metal-clad laminate, wherein the adhesive layer has a thickness of 0.3 to 3.0 µm.   The three-layer flexible metal-clad laminate according to claim 1, wherein the adhesive layer has a thickness of 0.3 to 1.5 μm.   The three-layer flexible metal-clad laminate according to claim 1, wherein the adhesive layer includes an epoxy resin.   The three-layer flexible metal-clad laminate according to claim 3, wherein the adhesive layer does not include a halogen-based flame retardant and a phosphorus-based flame retardant.   The three-layer flexible metal-clad laminate according to claim 1 or 2, wherein the adhesive layer includes a polyimide resin.   The three-layer flexible metal-clad laminate according to claim 1, wherein the resin layer is made of a polyimide film.   The three-layer flexible metal-clad laminate according to any one of claims 1 to 6, wherein the metal layer pulling-off force is 7 N / cm or more. A resin layer having a first main surface and a second main surface, and a first adhesive layer and a first metal layer are laminated in this order on the first main surface, and the second main surface has Is a double-sided three-layer flexible metal-clad laminate in which a second adhesive layer and a second metal layer are laminated in this order,
The 10-point average roughness (Rz) of the surfaces of the first metal layer on the first adhesive layer side and the second metal layer on the second adhesive layer side is 0.05 to 0.25 μm. The surface area ratio is from 1.0001 to 1.010,
A double-sided, three-layer flexible metal-clad laminate, wherein the first adhesive layer and the second adhesive layer have a thickness of 0.3 to 3.0 µm.   The double-sided three-layer flexible metal-clad laminate according to claim 8, wherein the adhesive layer has a thickness of 0.3 to 1.5 μm.   The double-sided three-layer flexible metal-clad laminate according to claim 8 or 9, wherein the adhesive layer contains an epoxy resin.   The double-sided, three-layer flexible metal-clad laminate according to claim 10, wherein the adhesive layer does not contain a halogen-based flame retardant and a phosphorus-based flame retardant.   The double-sided three-layer flexible metal-clad laminate according to claim 8 or 9, wherein the adhesive layer contains a polyimide resin.   The three-layer flexible metal-clad laminate according to claim 8, wherein the resin layer is made of a polyimide film.   The double-sided three-layer flexible metal-clad laminate according to any one of claims 8 to 13, wherein the metal layer pulling-off force is 7 N / cm or more.

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