TW201728445A - Low-dielectric flame-resistant adhesive composition - Google Patents

Abstract

Provided is a laminate that exhibits good adhesion properties with respect to not only conventional polyimide and polyester films but also to metal substrates and low polarity resin substrates, such as LCP, and that can attain high solder heat resistance and has excellent low-dielectric characteristics and flame resistance. This laminate (Z) is obtained by stacking a resin substrate and a metal substrate with an adhesive layer therebetween, the adhesive layer comprising a carboxyl-containing polyolefin resin (A). The laminate (Z) is characterized in that: (1) the adhesive layer has a specific permittivity ([epsilon]c) of at most 3.0 at the frequency of 1 MHz; (2) the adhesive layer has a dielectric tangent (tan[delta]) of at most 0.02 at the frequency of 1 MHz; (3) the peel strength of the resin substrate and the metal substrate is at least 0.5 N/mm; (4) the laminate (Z) has a moist solder heat resistance of at least 240 DEG C; and (5) a laminate (X) of the adhesive layer and the resin substrate indicates VTM-0 by UL-94 standard.

Description

Low dielectric flame retardant adhesive composition

The present invention relates to a laminate comprising an adhesive layer exhibiting low dielectric constant, low dielectric tangent, and flame retardancy. More specifically, the present invention relates to a laminate in which a resin substrate and a metal substrate are laminated via an adhesive which exhibits a low dielectric constant, a low dielectric tangent, and a flame retardant. In particular, a laminate for a flexible printed circuit board (hereinafter abbreviated as FPC), a surface coating film containing the laminate, a laminate, a copper foil with a resin, and a bonding sheet.

In recent years, with the increase in the speed of transmission signals in printed circuit boards, high frequency signals are being developed. At the same time, there is an increasing demand for low dielectric properties (low dielectric constant, low dielectric tangent) of the FPC in the high frequency region. As a substrate film used for FPC, a substrate film such as liquid crystal polymer (LCP), aligned polystyrene (SPS), or polyphenylene sulfide (PPS) having low dielectric properties has been proposed. It replaces the conventional polyimide (PI) and polyethylene terephthalate film. However, the base film having a low dielectric property has a low polarity, and it is difficult to produce a FPC member such as a cover film or a laminate when a conventional epoxy-based adhesive or an acrylic adhesive is used. (for example, Patent Documents 1, 2). Further, the epoxy-based adhesive or the acrylic-based adhesive is not excellent in low dielectric properties, and the dielectric properties of the FPC are impaired. Further, the adhesive composition used for the above purpose is mostly flammable, and it is required to impart flame retardancy. The flame retardant uses a system of a halogen-based organic compound to have excellent flame retardancy. However, this method has a problem that corrosive halogen gas is generated upon burning. Therefore, a halogen-free flame retardant which does not contain a halogen component is sought. For example, blending of a phosphorus-based flame retardant is employed. For example, in Patent Document 3, it is considered that an organic phosphinate as a flame retardant can be used, and the content range of the flame retardant when the flame retardant is contained in the surface coating film described in the same document is shown. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 2014-34668

[Problems to be Solved by the Invention] However, Patent Document 1 describes the adhesion between polyimide and rolled copper foil, solder heat resistance, and flame retardancy. However, low dielectric properties are not mentioned, and it is difficult to obtain Adhesion of a substrate film having low dielectric properties such as LCP. Further, Patent Document 2 describes the adhesion between polyimide and copper foil, solder heat resistance, insulation reliability, and flame retardancy. However, dielectric properties are not mentioned, and there is no mention of having an LCP or the like. Adhesion of a substrate film having low dielectric properties. Although the dielectric constant and the flame retardancy are described in Patent Document 3, only the adhesion between the copper foil and the copper foil is touched, and the adhesion to the polyimide and the LCP substrate is not mentioned. Also, there is no mention of the solder heat resistance required for FPC use.

As a result of intensive studies to solve the above problems, the present inventors have found that a binder layer having a specific physical property has low dielectric properties not only with conventional polyimides, polyethylene terephthalate films, and LCPs. The metal substrate such as a resin substrate or a copper foil has high adhesion, high solder heat resistance, and low dielectric properties, and further has flame retardancy based on UL-94 VTM-0, and completed the present invention.

That is, the present invention has been made in an effort to provide a laminate having good adhesion to various resin substrates such as polyimide and LCP and a metal substrate, and having heat resistance and low dielectric properties. Excellent flame retardancy. [Means for solving the problem]

A laminate (Z) comprising a resin substrate and a metal substrate laminated via an adhesive comprising a carboxyl group-containing polyolefin resin (A); characterized by: (1) an adhesive layer at a frequency of 1 MHz The relative dielectric constant (ε _c ) is 3.0 or less, (2) the dielectric tangent (tan δ) of the adhesive layer at a frequency of 1 MHz is 0.02 or less, and (3) the peel strength between the resin substrate and the metal substrate is 0.5. N/mm or more, (4) The heat resistance of the wet solder of the laminate (Z) is 240 ° C or higher, and (5) the laminate (X) obtained by removing the metal substrate from the laminate (Z) is In the UL-94 method, it is VTM-0.

A laminate (X), which is a laminate of a resin substrate and a metal substrate, which is formed by laminating a layer of an adhesive including a carboxyl group-containing polyolefin resin (A). a laminate of the resin substrate; characterized in that: (1) the dielectric constant (ε _c ) of the adhesive layer at a frequency of 1 MHz is 3.0 or less, and (2) dielectric tangent of the adhesive layer at a frequency of 1 MHz (tan δ) is 0.02 or less, and (3) when a metal substrate is laminated on the adhesive layer of the laminate (X), the peel strength between the resin substrate and the metal substrate in the laminate is 0.5 N/mm. As described above, (4) when a metal substrate is laminated on the adhesive layer of the laminate (X), the heat resistance of the solder of the laminate is 240 ° C or higher, and (5) the laminate (X) is in the UL- In the 94 method, it is VTM-0.

A laminate (Y), which is a laminate of a resin substrate and a metal substrate, which is formed by laminating a layer of an adhesive including a carboxyl group-containing polyolefin resin (A). a laminate of the metal substrate; characterized in that: (1) the dielectric constant (ε _c ) of the adhesive layer at a frequency of 1 MHz is 3.0 or less, and (2) dielectric tangent of the adhesive layer at a frequency of 1 MHz (tan δ) is 0.02 or less, and (3) when a resin substrate is laminated on the adhesive layer of the laminate (Y), the peel strength between the resin substrate and the metal substrate in the laminate is 0.5 N/mm. (4) When the resin substrate is laminated on the adhesive layer of the laminate (Y), the heat resistance of the solder of the laminate is 240 ° C or higher, and (5) subsequent to the laminate (Y) The laminate layer of the resin substrate is laminated to form a laminate (Z), and then the laminate (X) obtained by removing the metal substrate is VTM-0 in the UL-94 method.

An adhesive layer used as a laminate (Z) of a resin substrate and a metal substrate via a laminate layer comprising an adhesive layer of a carboxyl group-containing polyolefin resin (A); (1) The relative dielectric constant (ε _c ) of the adhesive layer at a frequency of 1 MHz is 3.0 or less, and (2) the dielectric tangent (tan δ) of the adhesive layer at a frequency of 1 MHz is 0.02 or less, and (3) When the resin substrate is laminated on one surface of the layer, and the metal substrate is laminated on the other surface, the peel strength between the resin substrate and the metal substrate in the laminate is 0.5 N/mm or more, and (4) When the resin substrate is laminated on one surface of the agent layer and the metal substrate is laminated on the other surface, the heat resistance of the solder of the laminate is 240 ° C or higher, and (5) the resin base is laminated on one side of the adhesive layer. The laminate (X) obtained after the material was VTM-0 in the UL-94 method.

A back sheet comprising the laminate (Z), the laminate (X), the laminate (Y) or an adhesive layer. A printed circuit board comprising the above-described succeeding film as a constituent element. [Effects of the Invention]

The laminate (Z) in which the resin substrate and the metal substrate of the present invention are laminated via an adhesive including a carboxyl group-containing polyolefin resin (A), and (1) the adhesive layer at a relative frequency of 1 MHz. The dielectric constant (ε _c ) is 3.0 or less, (2) the dielectric tangent (tan δ) of the adhesive layer at a frequency of 1 MHz is 0.02 or less, and (3) the peel strength between the resin substrate and the metal substrate is 0.5 N/ (m) The heat resistance of the wet solder of the laminate (Z) is 240 ° C or higher, and (5) The laminate (X) of the adhesive layer and the resin substrate is VTM-0 in the UL-94 method. . Not only the conventional polyimide, polyester film, and low-polarity resin substrate such as LCP, but also a metal substrate, it has high adhesion, and it can obtain high solder heat resistance, and is excellent in low dielectric properties and flame retardancy.

Hereinafter, embodiments of the present invention will be described in detail. The laminate of the resin substrate and the metal substrate of the present invention comprising a layer of an adhesive comprising a carboxyl group-containing polyolefin satisfies the following (1) to (5).

<Carboxyl group-containing polyolefin resin (A)> The carboxyl group-containing polyolefin resin (A) (hereinafter also referred to simply as (A) component) used in the present invention is not limited, and is preferably an α,β-unsaturated carboxylic acid. It is preferred that at least one of the anhydrides and the acid anhydride thereof are grafted to the polyolefin resin. The polyolefin resin refers to a homopolymer of an olefin monomer exemplified as ethylene, propylene, butylene, butadiene, isoprene or the like, or a copolymer with other monomers, and a hydride of the obtained polymer. Or a polymer such as a halide which is mainly composed of a hydrocarbon skeleton. That is, in the case of the carboxyl group-containing polyolefin, it is preferred to graft at least one of the α,β-unsaturated carboxylic acid and its anhydride to at least one of the polyethylene, the polypropylene, and the propylene-α-olefin copolymer. One type is preferred.

The propylene-α-olefin copolymer is mainly obtained by copolymerizing propylene with an α-olefin. As the α-olefin, for example, one or more of ethylene, 1-butene, 1-heptene, 1-octene, 4-methyl-1-pentene, and vinyl acetate can be used. Among these α-olefins, ethylene and 1-butene are preferred. The ratio of the propylene component to the α-olefin component of the propylene-α-olefin copolymer is not limited, and the propylene component is preferably 50 mol% or more, more preferably 70 mol% or more.

Examples of at least one of the α,β-unsaturated carboxylic acid and the acid anhydride thereof include maleic acid, itaconic acid, citraconic acid, and the like. These anhydrides are preferred, and maleic anhydride is preferred. Specific examples thereof include maleic anhydride-modified polypropylene, maleic anhydride-modified propylene-ethylene copolymer, maleic anhydride-modified propylene-butene copolymer, and maleic anhydride-modified propylene-ethylene-butene copolymer. One or a combination of two or more kinds of these acid-modified polyolefins can be used in combination.

The acid value of the carboxyl group-containing polyolefin resin (A) is preferably 100 equivalents/10 ⁶ g or more, and 200 equivalents or less, in view of heat resistance and adhesion to a resin substrate or a metal substrate. More preferably ⁶ g or more, and 250 equivalents/10 ⁶ g is particularly preferred. When the value is not reached, the compatibility with the epoxy resin (D) or the carbodiimide resin (C) may be low, and the bonding strength may not be exhibited. Further, there is a case where the crosslinking density is low and heat resistance is lacking. The upper limit is preferably 1000 equivalents/10 ⁶ g or less, more preferably 700 equivalents/10 ⁶ g or less, and particularly preferably 500 equivalents/10 ⁶ g or less. If the value exceeds the above value, there is a case where the adhesion is lowered. Further, there is a case where the viscosity and stability of the solution are lowered and the pot life characteristics are lowered. Further manufacturing efficiency is also reduced, which is not good.

The weight average molecular weight (Mw) of the carboxyl group-containing polyolefin resin (A) is preferably in the range of 10,000 to 180,000. The range of 20,000 to 160,000 is better, the range of 30,000 to 150,000 is particularly good, the range of 40,000 to 140,000 is particularly good, and the range of 50,000 to 130,000 is the best. If the above value is not reached, there is a case where the cohesive force is weak and the adhesion is poor. On the other hand, when the value is more than the above value, there is a case where the fluidity is low and the operability at the time is problematic.

The method for producing the carboxyl group-containing polyolefin resin (A) is not particularly limited, and examples thereof include a radical graft reaction (that is, a radical species are generated for a polymer which becomes a main chain, and the radical species is used as a polymerization initiation). The unsaturated carboxylic acid and the acid anhydride are subjected to graft polymerization (such as graft polymerization).

The radical generator is not particularly limited, and an organic peroxide is preferably used. The organic peroxide is not particularly limited, and examples thereof include di-tert-butyl peroxybenzeneate, t-butyl hydroperoxide, dicumyl peroxide, benzammonium peroxide, and benzoic acid peroxide. a butyl ester, a third butyl peroxy-2-ethylhexanoate, a third butyl peroxypivalate, a methyl ethyl ketone peroxide, a di-tert-butyl peroxide, a peroxide such as laurel; Azonitrile such as azobisisobutyronitrile or azobisisopropionitrile.

<Adhesive Layer> In the present invention, the adhesive layer refers to a layer of an adhesive composition obtained by applying an adhesive composition to a substrate and drying the composition. The thickness of the layer is not particularly limited, but is preferably 5 μm or more, more preferably 10 μm or more, and still more preferably 15 μm or more. Further, it is preferably 200 μm or less, more preferably 100 μm or less, and particularly preferably 50 μm or less. When the thickness is too small, it is difficult to obtain sufficient adhesion performance. When the thickness is too large, there is a problem that the residual solvent is likely to increase due to insufficient drying, and the embossing occurs during pressing at the time of production of the printed circuit board.

The method of applying the adhesive composition to the substrate is not particularly limited, and examples thereof include a chamfer coater and a reverse roll coater. Alternatively, the adhesive layer may be provided directly or by a transfer method on a rolled copper foil or a polyimide film which is a constituent material of the printed circuit board. The drying conditions are not particularly limited, and the residual solvent ratio after drying is preferably 1% by mass or less. When the amount is more than 1% by mass, there is a problem that the residual solvent is foamed at the time of pressing the printed circuit board to cause bulging.

<Resin base material> The resin base material in the present invention is not particularly limited as long as it can be applied to the adhesive composition of the present invention and dried to form an adhesive layer, and is preferably a resin substrate such as a film-like resin ( Hereinafter, it is also referred to as a base film layer). Specifically, a polyester resin, a polyamide resin, a polyimide resin, a polyamidimide resin, a liquid crystal polymer (LCP), a polyphenylene sulfide, a para-polystyrene, a polyolefin system can be exemplified. Resin, fluorine resin, etc. As a commercial item of the LCP film, for example, Vecstar (registered trademark) manufactured by KURARAY Co., Ltd. can be cited. In addition, as a commercial item of a polyimine film, Apical (registered trademark) by Kaneka Co., Ltd. is mentioned, for example.

The thickness of the resin substrate is not particularly limited, but is preferably 1 μm or more, more preferably 3 μm or more, and still more preferably 10 μm or more. Further, it is preferably 50 μm or less, more preferably 30 μm or less, and particularly preferably 20 μm or less. When the thickness is too small, it may be difficult to obtain sufficient electrical performance in the circuit. On the other hand, when the thickness is too thick, the processing efficiency at the time of circuit production may be lowered. Further, the relative dielectric constant (? _c ) of the resin substrate is preferably 5.0 or less, more preferably 4.0 or less, and even more preferably 3.5 or less. The lower limit value is not particularly limited, and it is not problematic if it is industrially 0.1 or more.

<Metal substrate> As the metal substrate, any conventionally known conductive material that can be used for a circuit board can be used. Examples of the material include various metals such as SUS, copper, aluminum, iron, steel, zinc, and nickel, and alloys, plating materials, and metals treated with other metals such as zinc or chromium compounds. A metal foil is preferred, and a copper foil is preferred. The thickness of the metal foil is not particularly limited, but is preferably 1 μm or more, more preferably 3 μm or more, and still more preferably 10 μm or more. Further, it is preferably 50 μm or less, more preferably 30 μm or less, and particularly preferably 20 μm or less. When the thickness is too small, it may be difficult to obtain sufficient electrical performance in the circuit. On the other hand, when the thickness is too thick, the processing energy rate at the time of circuit production may be lowered. The metal foil is usually provided in the form of a reel. The form of the metal foil used in the production of the printed wiring board of the present invention is not particularly limited. When a metal foil in a strip form is used, the length is not particularly limited. Further, the width thereof is not particularly limited, and is preferably about 250 to 500 cm.

<Laminate> The laminate (Z)-based resin substrate of the present invention and the metal substrate are laminated with an adhesive layer (a resin laminate/adhesive layer/three-layer laminate of a metal substrate). Laminate (X)-based resin substrate and adhesive layer laminated layer (resin base material/adhesive layer), laminate (Y)-based metal substrate and adhesive layer laminated layer (metal substrate) / adhesive layer). In the present invention, the laminate (X), the laminate (Y), and the laminate (Z) may be collectively referred to as a laminate. The laminate (X) can be obtained by applying an adhesive composition to a resin substrate by a conventional method and drying. Further, the laminate (Y) can be obtained by applying the adhesive composition to a metal substrate by a conventional method and drying. The laminate (Z) can be obtained by laminating a metal substrate or a resin substrate in a laminate (X) or a laminate (Y), respectively. A release substrate may be laminated on the surface of the laminate layer of the laminate (X) or the laminate (Y). Further, an adhesive layer (adhesive layer/resin substrate/adhesive layer/metal substrate, resin substrate/adhesive layer/metal) is further laminated on the resin substrate or the metal substrate of the laminate (Z). The substrate/adhesive layer, the adhesive layer/resin substrate/adhesive layer/metal substrate/adhesive layer may also be used.

The laminate of the present invention more satisfies the following requirements (1) to (5).

<Requirements (1)> Explain the requirements (1). In the laminate (Z) of the invention of the present invention, the relative dielectric constant (? _c ) of the adhesive layer at a frequency of 1 MHz is required to be 3.0 or less. Specifically, the adhesive composition was applied to a release substrate so that the thickness after drying became 25 μm, and dried at about 130 ° C for about 3 minutes. Then, it is heat-treated at about 140 ° C for about 4 hours to be hardened, and the hardened adhesive composition layer (adhesive layer) is peeled off from the release film. The relative dielectric constant (? _c ) of the adhesive composition layer after peeling at a frequency of 1 MHz was measured. The relative dielectric constant (? _c ) is 3.0 or less, preferably 2.6 or less, and more preferably 2.3 or less. The lower limit is not particularly limited, and is practically 2.0. Further, the relative dielectric constant (? _c ) of the entire region at a frequency of 1 MHz to 10 GHz is preferably 3.0 or less, more preferably 2.6 or less, and particularly preferably 2.3 or less.

The relative dielectric constant (? _c ) of the adhesive layer in the laminate (Z) can be measured as follows. In other words, a method in which the metal substrate of the laminate (Z) is removed by an etching solution to obtain a two-layer laminate (X) of the adhesive layer and the resin substrate can be exemplified. The etching liquid is not particularly limited, and an iron chloride (III) aqueous solution, a copper chloride (II) aqueous solution, a sulfuric acid hydrogen peroxide aqueous mixed solution, an alkali etching solution, a nickel etching solution, or the like can be used. Then, the resin substrate of the laminate (X) is peeled off (removed), and a metal layer is formed on both surfaces of the remaining adhesive layer by a thin film method such as vapor deposition or sputtering or a method of applying a conductive paste. The capacitance was measured as a capacitor, and the relative dielectric constant (ε _c ) was calculated from the thickness and the area. Further, in another method, a metal layer can be formed on the surface of the resin substrate of the laminate (X) by the above method as a capacitor, and the combined capacitance relative dielectric constant of the resin substrate and the adhesive layer can be measured ( After ε _c ), the metal layer and the adhesive layer were peeled off (removed) from the laminate (X), and a capacitor was produced in the same manner, and the capacitance was measured, and the relative dielectric constant (ε _c ) of the remaining resin substrate was measured. The dielectric layer of the capacitor obtained from the laminate (X) is regarded as a multilayer dielectric of a resin substrate and an adhesive layer, so that the relative dielectric constant (ε _c ) of the adhesive layer can be calculated from the difference between the two. .

<Requirement (2)> Explain the requirements (2). In the laminate (Z) of the invention of the present invention, the dielectric tangent (tan δ) at a frequency of 1 MHz of the adhesive layer needs to be 0.02 or less. Specifically, the adhesive composition was applied to a release substrate so that the thickness after drying became 25 μm, and dried at about 130 ° C for about 3 minutes. Then, it is heat-treated at about 140 ° C for about 4 hours to be hardened, and the hardened adhesive composition layer (adhesive layer) is peeled off from the release film. The dielectric tangent (tan δ) of the adhesive composition at a frequency of 1 MHz was measured after peeling. The dielectric tangent (tan δ) is 0.02 or less, preferably 0.01 or less, more preferably 0.005 or less. The lower limit is not particularly limited, but is practically 0.0001. Further, the dielectric tangent (tan δ) in the entire region of the frequency of 1 MHz to 10 GHz is preferably 0.02 or less, more preferably 0.01 or less, and particularly preferably 0.005 or less.

The dielectric tangent (tan δ) of the adhesive layer in the laminate (Z) can also be measured by the same operation as the dielectric constant described above.

<Requirements (3)> Explain the requirements (3). In the laminate (Z) of the invention of the present invention, the peel strength between the resin substrate and the metal substrate needs to be 0.5 N/mm or more. Specifically, the adhesive composition was applied to a resin substrate so that the thickness after drying became 25 μm, and dried at about 130° C. for about 3 minutes. Then, a metal substrate is bonded to the surface of the adhesive composition layer (adhesive layer). The bonding is carried out in such a manner that the shiny side of the metal substrate is brought into contact with the adhesive composition layer, and vacuum-pressed at about 160 ° C under a pressure of about 40 kgf / cm ² for about 30 seconds. Then, it was heat-treated at about 140 ° C for about 4 hours to be hardened to prepare a three-layer laminate (Z) of a resin substrate / an adhesive layer / a metal substrate. The resin substrate of the laminate (Z) was peeled at 90° at a tensile speed of 50 mm/min at room temperature (about 25° C.), and the peel strength was measured. The 90° peel strength needs to be 0.5 N/mm or more, preferably 0.8 N/mm or more, more preferably 1.0 N/mm or more. Further, even the laminate (Z) obtained by a method other than the above method is included in the present invention as long as the 90° peel strength is 0.5 N/mm or more.

The laminate (Z) of the present invention can be obtained by laminating a metal substrate from the surface of the adhesive composition layer (adhesive layer) of the laminate (X) from the laminate (X). The bonding is carried out in such a manner that the shiny side of the metal substrate is brought into contact with the adhesive composition layer, and vacuum-pressed at about 160 ° C under a pressure of about 40 kgf / cm ² for about 30 seconds. Then, it was heat-treated at about 140 ° C for about 4 hours to be hardened to prepare a three-layer laminate (Z) of a resin substrate / an adhesive layer / a metal substrate. The resin substrate of the laminate (Z) was peeled at 90° at a tensile speed of 50 mm/min at room temperature (about 25° C.), and the peel strength was measured. The 90° peel strength needs to be 0.5 N/mm or more, preferably 0.8 N/mm or more, more preferably 1.0 N/mm or more.

The laminate (Z) of the present invention can be obtained by laminating a resin substrate on the surface of the adhesive composition layer (adhesive layer) of the laminate (Y) from the laminate (Y). The bonding is carried out in such a manner that the resin substrate is brought into contact with the adhesive composition layer, and vacuum-pressed at about 160 ° C under a pressure of about 40 kgf / cm ² for about 30 seconds. Then, it was heat-treated at about 140 ° C for about 4 hours to be hardened to prepare a three-layer laminate (Z) of a resin substrate / an adhesive layer / a metal substrate. The resin substrate of the laminate (Z) was peeled at 90° at a tensile speed of 50 mm/min at room temperature (about 25° C.), and the peel strength was measured. The 90° peel strength needs to be 0.5 N/mm or more, preferably 0.8 N/mm or more, more preferably 1.0 N/mm or more.

The laminate (Z) of the present invention can be obtained by bonding a resin substrate to one surface of the adhesive layer and bonding the shiny surface of the metal substrate to the other surface from the adhesive layer. In the bonding, the release substrate/adhesive layer and the resin substrate are subjected to roll lamination at a pressure of about 3 kgf/cm ² at about 100 ° C for about 1 m/min, and after lamination, the release substrate is peeled off. The vacuum surface of the metal substrate is brought into contact with the adhesive layer in a vacuum at about 160 ° C under a pressure of about 40 kgf / cm ² for about 30 seconds. Then, it was heat-treated at about 140 ° C for about 4 hours to be hardened to prepare a three-layer laminate (Z) of a resin substrate / an adhesive layer / a metal substrate. The resin substrate of the laminate (Z) was peeled at 90° at a tensile speed of 50 mm/min at room temperature (about 25° C.), and the peel strength was measured. The 90° peel strength needs to be 0.5 N/mm or more, preferably 0.8 N/mm or more, more preferably 1.0 N/mm or more.

<Requirement (4)> Explain the requirement (4). In the laminate (Z) of the invention of the present invention, the heat resistance of the humidifying solder needs to be 240 ° C or higher. Specifically, the adhesive composition was applied to a resin substrate so that the thickness after drying became 25 μm, and dried at about 130° C. for about 3 minutes. Then, a metal substrate is bonded to the surface of the adhesive composition layer (adhesive layer). The bonding is carried out in such a manner that the shiny side of the metal substrate is brought into contact with the adhesive composition layer, and vacuum-pressed at about 160 ° C under a pressure of about 40 kgf / cm ² for about 30 seconds. Then, it was heat-treated at about 140 ° C for about 4 hours to be hardened to prepare a three-layer laminate (Z) of a resin substrate / an adhesive layer / a metal substrate. The laminate (Z) was treated under conditions of about 40 ° C and about 80 RH% for about 72 hours, and was allowed to flow in a molten solder bath at each temperature for 1 minute, and the temperature at which no change in appearance such as bulging was caused was measured. The heat resistance of the moisturizing solder needs to be 240 ° C or higher, preferably 250 ° C or higher, and more preferably 260 ° C or higher. Further, even the laminate (Z) obtained by a method other than the above method is included in the present invention as long as the heat resistance of the solder is 240 ° C or higher.

The laminate (Z) of the present invention can be obtained by laminating a metal substrate from the surface of the adhesive composition layer (adhesive layer) of the laminate (X) from the laminate (X). The bonding is carried out in such a manner that the shiny side of the metal substrate is brought into contact with the adhesive composition layer, and vacuum-pressed at about 160 ° C under a pressure of about 40 kgf / cm ² for about 30 seconds. Then, it was heat-treated at about 140 ° C for about 4 hours to be hardened to prepare a three-layer laminate (Z) of a resin substrate / an adhesive layer / a metal substrate. The laminate (Z) was treated under conditions of about 40 ° C and about 80 RH% for about 72 hours, and was allowed to flow in a molten solder bath at each temperature for 1 minute, and the temperature at which no change in appearance such as bulging was caused was measured. The heat resistance of the moisturizing solder needs to be 240 ° C or higher, preferably 250 ° C or higher, and more preferably 260 ° C or higher.

The laminate (Z) of the present invention can be obtained by laminating a resin substrate on the surface of the adhesive composition layer (adhesive layer) of the laminate (Y) from the laminate (Y). The bonding is carried out in such a manner that the resin substrate is brought into contact with the adhesive composition layer, and vacuum-pressed at about 160 ° C under a pressure of about 40 kgf / cm ² for about 30 seconds. Then, it was heat-treated at about 140 ° C for about 4 hours to be hardened to prepare a three-layer laminate (Z) of a resin substrate / an adhesive layer / a metal substrate. The laminate (Z) was treated under conditions of about 40 ° C and about 80 RH% for about 72 hours, and was allowed to flow in a molten solder bath at each temperature for 1 minute, and the temperature at which no change in appearance such as bulging was caused was measured. The heat resistance of the moisturizing solder needs to be 240 ° C or higher, preferably 250 ° C or higher, and more preferably 260 ° C or higher.

Further, the laminate (Z) of the present invention can be obtained by bonding a resin substrate to one surface of the adhesive layer and bonding the shiny surface of the metal substrate to the other surface. After bonding, the adhesive layer is bonded to the resin substrate, and the shiny surface of the metal substrate is brought into contact with the adhesive layer, and vacuum-pressed at about 160 ° C under a pressure of about 40 kgf / cm ² . Seconds and then. Then, it was heat-treated at about 140 ° C for about 4 hours to be hardened to prepare a three-layer laminate (Z) of a resin substrate / an adhesive layer / a metal substrate. The laminate (Z) was treated under conditions of about 40 ° C and about 80 RH% for about 72 hours, and was allowed to flow in a molten solder bath at each temperature for 1 minute, and the temperature at which no change in appearance such as bulging was caused was measured. The heat resistance of the moisturizing solder needs to be 240 ° C or higher, preferably 250 ° C or higher, and more preferably 260 ° C or higher.

<Requirements (5)> Explain the requirements (5). In the laminate (Z) of the present invention, when the laminate (X) constituting the laminate (Z) is evaluated by the UL-94 flame retardancy evaluation test, it is required to be VTM-0. Specifically, the adhesive composition of the present invention was applied to a resin substrate so that the thickness after drying became 25 μm, and dried at about 130 ° C for about 3 minutes. Then, it was heat-treated at about 140 ° C for about 4 hours to be hardened, and a test piece (50 ± 0.5 mm × 200 ± 0.5 mm) was cut out from the obtained laminate (X), and the thickness was measured. The test piece was rounded into a cylindrical shape having a length of 200 mm and a diameter of about 10 mm and fixed to a stand. The flame of the gas burner was adjusted to a height of about 20 mm, and the lower end of the test piece was brought into contact with the flame for 3 sec, and the burning time was measured. The flame was repeatedly contacted twice per sample. When the burning time was 10 sec or less, and the total burning time of 2 times was 30 sec or less, it was judged that it was a pass. The test was carried out with each N=5, and all qualified persons corresponded to VTM-0.

The metal substrate of the laminate (Z) is removed from the laminate (Z) by an etching solution, and a laminate (X) of two layers of the adhesive layer and the resin substrate can be obtained. The etching liquid is not particularly limited, and an iron chloride (III) aqueous solution, a copper chloride (II) aqueous solution, a sulfuric acid hydrogen peroxide aqueous mixed solution, an alkali etching solution, a nickel etching solution, or the like can be used.

The laminate (Z) is obtained by laminating a resin substrate on the surface of the adhesive composition layer (adhesive layer) of the laminate (Y) from the laminate (Y), and then the laminate is obtained. The metal substrate of (Z) is removed by an etching solution to obtain a laminate (X).

<Adhesive Composition> The adhesive composition used in the present invention is at least a carboxyl group-containing polyolefin resin (A). The laminate of the carboxyl group-containing polyolefin resin (A) and the adhesive layer composed of the adhesive composition can exhibit the excellent properties of the above (1) to (5).

In addition to the component (A), the adhesive composition of the present invention preferably includes a carboxyl group-containing styrene resin (B) (hereinafter also referred to simply as (B) component), and a carbodiimide resin (C) (hereinafter also The epoxy resin (D) (hereinafter also referred to simply as (D) component) and/or the flame-retardant filler (E) (hereinafter also referred to simply as (E) component) are preferably referred to as (C) component. The five kinds of resins including the components (A) to (E) described above are not only a low-polarity resin substrate or a metal such as an LCP film which is not expected from conventional polyimides and polyester films, and which are not contemplated by the prior art. The substrate also has high adhesion and is excellent in solder heat resistance, electrical properties (low dielectric properties), and flame retardancy.

<Carboxyl group-containing styrene resin (B)> The carboxyl group-containing styrene resin (B) which can be used in the invention is not limited, and it is preferred to use an aromatic vinyl compound alone or an aromatic vinyl compound and a conjugated diene. The copolymer of the compound and/or the random structure of the copolymer and the hydride thereof are preferably modified with an unsaturated carboxylic acid. The aromatic vinyl compound is not particularly limited, and examples thereof include styrene, t-butyl styrene, α-methyl styrene, p-methyl styrene, divinyl benzene, and 1,1-diphenyl styrene. , N,N-diethyl-p-aminoethylstyrene, vinyltoluene, p-tert-butylstyrene, and the like. Further, examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethyl-1,3-butadiene. Specific examples of the copolymer of the aromatic vinyl compound and the conjugated diene compound include styrene-ethylene-butylene-styrene block copolymer (SEBS) and styrene-ethylene-propylene-styrene embedded. Segment copolymer (SEPS), styrene-ethylene-ethylene, propylene-styrene block copolymer (SEEPS), and the like.

The modification of the carboxyl group-containing styrene resin (B) can be carried out, for example, by copolymerizing an unsaturated carboxylic acid during polymerization of a styrene resin. Further, it can be carried out by heating and kneading a styrene resin and an unsaturated carboxylic acid in the presence of an organic peroxide. The unsaturated carboxylic acid is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, maleic anhydride, itaconic anhydride, and fumaric anhydride.

The acid value of the carboxyl group-containing styrene resin (B) is preferably 10 equivalents/10 ⁶ g or more, and 100 equivalents or less, in view of heat resistance and adhesion to a resin substrate or a metal substrate. More preferably ⁶ g or more, and 150 equivalents/10 ⁶ g is particularly preferred. When the value is not reached, the compatibility with the epoxy resin (D) or the carbodiimide resin (C) is low, and the bonding strength may not be exhibited. Further, there is a case where the crosslinking density is low and heat resistance is lacking. The upper limit is preferably 1000 equivalents/10 ⁶ g or less, more preferably 700 equivalents/10 ⁶ g or less, and particularly preferably 500 equivalents/10 ⁶ g or less. When the value exceeds the above value, there is a case where the adhesion and the low dielectric property are lowered.

In the adhesive composition used in the present invention, the carboxyl group-containing styrene resin (B) is preferably contained in an amount of 5 to 95 parts by mass based on the carboxyl group-containing polyolefin resin (A) as a carboxyl group-containing styrene resin (B) 95. The range of ～5 parts by mass, that is, the component (A)/component (B) = 5 to 95/95 to 5 (mass ratio) is preferred. The component (A)/component (B) = 10 to 90/90 to 10 (mass ratio) is more preferable, and the range of (A) component / (B) component = 15 to 85 / 85 to 15 (mass ratio) is optimal. When the amount of the component (A) is less than the above value, the crosslinking density may be lowered, and the heat resistance of the moisturizing solder may be lowered. When the amount of the component (A) exceeds the above value, the wettability to the substrate may be lowered, and the strength may be lowered.

<Carbodiimide Resin (C)> The carbodiimide resin (C) is not particularly limited as long as it has a carbodiimide group in the molecule. A polycarbodiimide having two or more carbodiimide groups in the molecule is preferred. By using a carbodiimide resin (C), the carboxyl group-containing polyolefin resin (A) or the carboxyl group-containing styrene resin (B) carboxyl group is reacted with a carbodiimide to improve the composition of the adhesive and the substrate. Interaction and improved adhesion.

In the adhesive composition used in the present invention, the content of the carbodiimide resin (C) is preferably 100 parts by mass based on the total of the carboxyl group-containing polyolefin resin (A) and the carboxyl group-containing styrene resin (B). A range of 0.1 to 30 parts by mass is preferred. The range of 1 to 25 parts by mass is more preferably, and the range of 2 to 20 parts by mass is the best. If the value is not reached, there is a problem that the interaction with the substrate does not occur and the adhesion is lowered. When the value exceeds the above value, there is a problem that the pot life of the adhesive is shortened or the low dielectric property is lowered.

<Epoxy Resin (D)> The epoxy resin (D) is not particularly limited as long as it has an epoxy propyl group in the molecule, and it is preferred to have two or more epoxy propyl groups in the molecule. . Specifically, it is not particularly limited, but may be selected from biphenyl type epoxy resins, naphthalene type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, and novolak type epoxy resins. , alicyclic epoxy resin, dicyclopentadiene type epoxy resin, tetraepoxypropyl diaminodiphenylmethane, triepoxypropyl p-aminophenol, tetraepoxypropyl diamine At least one of the group consisting of cyclohexanone, N, N, N', N'-tetraepoxypropyl-m-xylylenediamine. It is preferably a bisphenol A type epoxy resin, a novolak type epoxy resin or a dicyclopentadiene type epoxy resin.

In the adhesive composition used in the present invention, the content of the epoxy resin (D) is preferably 1 part by mass based on 100 parts by mass of the total of the carboxyl group-containing polyolefin resin (A) and the carboxyl group-containing styrene resin (B). The range of 30 parts by mass is more preferable, the range of 2 to 15 parts by mass is more preferable, and the range of 3 to 10 parts by mass is most preferable. If it is less than the above range, sufficient hardening effect, adhesiveness, and heat resistance may not be obtained. Moreover, if it exceeds the above range, there is a problem that the pot life of the adhesive is shortened or the low dielectric properties are lowered.

<Flame-retardant filler (E)> The flame-retardant filler (E) is not particularly limited, and is preferably one which is insoluble in an organic solvent, and examples thereof include an inorganic flame-retardant filler and an organic flame-retardant filler. Examples of the inorganic flame-retardant filler include metal hydroxides such as aluminum hydroxide, magnesium hydroxide, zirconium hydroxide, calcium hydroxide, and barium hydroxide; and basic magnesium carbonate, zinc carbonate, magnesium carbonate-calcium, and carbonic acid. a metal carbonate compound such as calcium or barium carbonate; a metal oxide such as magnesium oxide, molybdenum oxide, zirconium oxide, tin oxide, tin oxide hydrate or cerium oxide; a metal boric acid compound such as zinc borate, zinc metaborate or barium metaborate; Inorganic metal compounds such as stone, magnesite, borax; inorganic phosphorus compounds such as red phosphorus. Examples of the organic flame-retardant filler include melamine phosphate, melamine polyphosphate, strontium phosphate, strontium polyphosphate, ammonium phosphate, ammonium polyphosphate, ammonium amide ammonium phosphate, ammonium polyphosphate ammonium phosphate, urethane phosphate, and polyphosphate. Ammonium phosphate, ginseng (diethylphosphinic acid) aluminum, ginseng (methylethylphosphinic acid) aluminum, ginseng (diphenylphosphinic acid) aluminum, bis(diethylphosphinic acid) zinc , bis(methylethylphosphinic acid) zinc, bis(diphenylphosphinic acid) zinc, bis(diethylphosphinic)oxytitanium, bismuth (diethylphosphinic acid) titanium, double (a) Phosphorus-based flame retardants such as oxytitanium oxyphosphonate, titanium hydride (methylethylphosphinic acid), titanium bis(diphenylphosphinic acid), titanium bismuth (diphenylphosphinic acid) ; melamine, melam, melamine cyanurate and other three compounds; cyanuric acid compounds, isocyanuric acid compounds, triazole compounds, tetrazole compounds, diazo compounds, urea and other nitrogen resistance A flammable agent; an antimony-based flame retardant such as a polyoxymethane compound or a decane compound. In the case of the flame-retardant filler, a metal hydroxide or a phosphorus compound is preferable, and among them, a phosphorus compound is more preferable, and for example, a known phosphorus-based flame retardant filler such as aluminum phosphinate can be used. Further, the phosphorus-based flame retardant has a type insoluble in an organic solvent (phosphorus-based flame-retardant filler) and a type which is soluble in an organic solvent (phosphorus-based flame-retardant non-filler), and is preferably insoluble in an organic solvent in the present invention. A type (phosphorus-based flame retardant filler) is preferred. The flame-retardant filler may be used singly or in combination of two or more.

In the adhesive composition of the present invention, the content of the flame-retardant filler is preferably in the range of 20 to 100 parts by mass, and preferably 30 to 90 parts by mass based on 100 parts by mass of the total of the components (A) to (D). The range is better, and the range of 40 to 90 parts by mass is particularly preferable. If the above range is not reached, it may be difficult to obtain flame retardancy. When it exceeds the above range, the adhesion, heat resistance, electrical properties, and the like may be deteriorated.

The adhesive composition used in the present invention may further contain an organic solvent. The organic solvent used in the present invention is a carboxyl group-containing polyolefin resin (A), a carboxyl group-containing styrene resin (B), a carbodiimide resin (C), and an epoxy resin (D). The solvent is not particularly limited. Specifically, for example, an aromatic hydrocarbon such as benzene, toluene or xylene; an aliphatic hydrocarbon such as hexane, heptane, octane or decane; cyclohexane, cyclohexene, methylcyclohexane or B; An alicyclic hydrocarbon such as cyclohexane; a halogenated hydrocarbon such as trichloroethylene, dichloroethylene, chlorobenzene or chloroform; an alcohol solvent such as methanol, ethanol, isopropanol, butanol, pentanol, hexanol, propylene glycol or phenol. a ketone solvent such as acetone, methyl isobutyl ketone, methyl ethyl ketone, pentanone, ketone, cyclohexanone, isophorone or acetophenone; acesulfame, ethyl acesulfame, etc.; An ester solvent such as methyl acetate, ethyl acetate, butyl acetate, methyl propionate or butyl formate; ethylene glycol mono-n-butyl ether, ethylene glycol monoisobutyl ether, ethylene glycol mono-tert-butyl ether, A glycol ether solvent such as diethylene glycol mono-n-butyl ether, diethylene glycol mono-isobutyl ether, triethylene glycol mono-n-butyl ether or tetraethylene glycol mono-n-butyl ether can be used. Species or more than two types.

The organic solvent is preferably in the range of 100 to 1000 parts by mass, and preferably 200 to 900 parts by mass, based on 100 parts by mass of the total of the carboxyl group-containing polyolefin resin (A) and the carboxyl group-containing styrene resin (B). The range is better, and the range of 300 to 800 parts by mass is the best. If it does not reach the above range, liquidity and pot life characteristics may be lowered. Moreover, if it exceeds the above range, there is a problem that it is disadvantageous in terms of manufacturing cost and transportation cost.

Further, the adhesive composition used in the present invention may further contain other components as necessary. Specific examples of the components include a tackifier, a filler different from the component (E), and a decane coupling agent.

<Adhesiveness-imparting agent> The adhesive composition used in the present invention may be blended with an adhesiveness-imparting agent if necessary. Examples of the adhesiveness-imparting agent include a polyterpene resin, a rosin-based resin, an aliphatic petroleum resin, an alicyclic petroleum resin, a copolymerized petroleum resin, a styrene resin, and a hydrogenated petroleum resin, etc., in order to improve the bonding strength. use. These may be used alone or in combination of two or more.

<Fillers different from the component (E)> The binder composition used in the present invention may be blended with a filler different from the component (E), such as ceria, if necessary. It is highly desirable to improve the heat resistance by blending cerium oxide. As the cerium oxide, hydrophobic cerium oxide and hydrophilic cerium oxide are generally known, and in order to impart moisture absorption resistance, it is preferred to use dimethyldichloromethane or hexamethyldioxane. Hydrophobic cerium oxide treated with octyl decane or the like. The blending amount of the cerium oxide is preferably 0.05 to 30 parts by mass based on 100 parts by mass of the total of the components (A) to (D). When it is less than 0.05 part by mass, the effect of improving heat resistance may not be exhibited. On the other hand, when the amount is more than 30 parts by mass, the dispersion of cerium oxide may occur, the viscosity of the solution may become too high, workability may be inconvenient, or the adhesion may be lowered.

<Hydrane coupling agent> In the adhesive composition used in the present invention, a decane coupling agent may be blended as necessary. It is highly desirable to improve the properties of the adhesion or heat resistance of the metal by blending the decane coupling agent. The decane coupling agent is not particularly limited, and examples thereof include those having an unsaturated group, those having an epoxy group, and those having an amine group. Among these, from the viewpoint of heat resistance, γ-glycidoxypropyltrimethoxydecane, β-(3,4-epoxycyclohexyl)ethyltrimethoxydecane, β-(3,4) A decane coupling agent having a glycidyl group such as epoxycyclohexyl)ethyltriethoxydecane is more preferable. The blending amount of the decane coupling agent is preferably from 0.5 to 20 parts by mass based on 100 parts by mass of the total of the components (A) to (D). When it is less than 0.5 part by mass, heat resistance may become unfavorable. On the other hand, when it exceeds 20 parts by mass, the heat resistance may be poor or the adhesion may be lowered.

<Continuous sheet> In the present invention, the laminate is formed by laminating the laminate (Z) and the release substrate via the adhesive composition, or in the laminate (X) or the laminate (Y). The release layer is formed by laminating a release substrate or laminating a release substrate on at least one of the adhesive layers. Specific examples of the composition include a release substrate/adhesive layer, a release substrate/adhesive layer/release substrate, a resin substrate/adhesive layer/release substrate, and a metal substrate/adhesive layer. / release base material, laminate / adhesive layer / release substrate, or release substrate / adhesive layer / laminate / adhesive layer / release substrate. By laminating the release substrate, the function as a protective layer of the substrate can be exhibited. Further, by using a release substrate, the release substrate can be released from the release sheet, and the adhesive layer can be transferred to another substrate.

The adhesive sheet of the present invention can be obtained by applying the adhesive composition used in the present invention to various laminates by a conventional method and drying. In addition, when the release substrate is attached to the adhesive layer after drying, the film can be wound without causing migration to the back surface of the substrate, and the workability is excellent, and the adhesive layer is protected, so that the storage property is excellent and the use is easy. Further, after application to the release substrate and drying, if another release substrate is attached as needed, the adhesive layer itself may be transferred to another substrate.

<Release base material> The release base material is not particularly limited, and examples thereof include a coating layer of a filler such as clay, polyethylene, or polypropylene on both sides of paper such as high-quality paper, kraft paper, rolled paper, or cellophane, and further A polyfluorene-based, fluorine-based or alkyd-based release agent is applied to each of the coating layers. Further, the above-mentioned release agent may be applied to various olefin films such as polyethylene, polypropylene, ethylene-α-olefin copolymer, propylene-α-olefin copolymer, and the like, and a film such as polyethylene terephthalate. Founder. Due to the release force between the release substrate and the adhesive layer, and the adverse effect of the polyoxygen on the electrical properties, it is preferable to perform polypropylene filling treatment on both sides of the high-quality paper and to use the alkyd-based release agent. It is preferred to use an alkyd-based release agent on the agent or on polyethylene terephthalate.

<Printed Circuit Board> The "printed circuit board" in the present invention includes a laminate formed of a metal foil forming a conductor circuit and a resin substrate as a constituent element. The printed circuit board can be produced, for example, by a conventionally known method such as a subtractive method using a metal-clad laminate. A so-called flexible circuit board (FPC), a flat cable, and a tape-type automatic bonding (TAB) which are partially or comprehensively coated with a surface film or a screen printing ink, if necessary, partially or comprehensively. A general term for boards and the like.

The printed circuit board of the present invention can be constructed as any laminate that can be used as a printed circuit board. For example, it may be a printed circuit board composed of four layers of a base film layer, a metal foil layer, an adhesive layer, and a surface coating layer. Further, for example, it may be a printed circuit board comprising five layers of a base film layer, an adhesive layer, a metal foil layer, an adhesive layer, and a surface coating layer.

Further, if necessary, a configuration may be adopted in which two or more of the above printed circuit boards are laminated.

The adhesive composition used in the present invention is suitable for use in each of the adhesive layers of a printed circuit board. In particular, when the adhesive composition used in the present invention is used as an adhesive, it is not only a conventional resin substrate such as a polyimine, a polyester film, a copper foil or an LCP which constitutes a printed circuit board. With high adhesion, solder reflow resistance is obtained, and the adhesive layer itself is excellent in low dielectric properties. Therefore, it is suitable as a binder composition used for a cover film, a laminated board, a copper foil with a resin, and an adhesive sheet.

In the printed circuit board of the present invention, any resin film which has been conventionally used as a substrate of a printed circuit board can be used as the base film. The resin of the base film may, for example, be a polyester resin, a polyamide resin, a polyimide resin, a polyamide amide resin, a liquid crystal polymer, a polyphenylene sulfide, a para-polystyrene, or a polyolefin. Resin, fluorine resin, etc. In particular, it has excellent adhesion even to low-polarity substrates such as liquid crystal polymers, polyphenylene sulfide, para-polystyrene, and polyolefin-based resins.

<Table Film> As the surface film, any conventionally known insulating film can be used as the insulating film for a printed circuit board. For example, polyimine, polyester, polyphenylene sulfide, polyether oxime, polyetheretherketone, aromatic polyamine, polycarbonate, polyarylate, polyamidimide, liquid crystal polymer can be used. A film made of various polymers such as polystyrene and polyolefin resin. A polyimide film or a liquid crystal polymer film is more preferable.

The printed circuit board of the present invention can be produced by any conventionally known process except for using the materials of the above layers.

In a preferred embodiment, the product is a semi-finished product (hereinafter referred to as "surface film side semi-finished product") which is produced by laminating a laminate layer. On the other hand, it is a semi-finished product (hereinafter referred to as "substrate film side two-layer semi-finished product") which is formed on a base film laminated metal foil layer to form a desired circuit pattern, or a base film laminated layer of an adhesive layer. A semi-finished product in which a metal foil layer is laminated thereon to form a desired circuit pattern (hereinafter referred to as "substrate film side three-layer semi-finished product") (hereinafter, the base film side two-layer semi-finished product and the base film side three-layer semi-finished product are combined It is called "substrate film side semi-finished product"). The film-side semi-finished product obtained in this manner is bonded to the base film-side semi-finished product to obtain a 4-layer or 5-layer printed circuit board.

The base film side semi-finished product can be obtained, for example, by a production method comprising the steps of: (A) applying a solution of the metal foil as a resin of the base film, and preliminary drying the coating film; (B) The step of heat-treating and drying the laminate of the metal foil obtained in the above (A) and the preliminary dried coating film (hereinafter referred to as "heat treatment and solvent removal step").

A conventionally known method can be used for forming the circuit in the metal foil layer. Additives can be used, and subtractive methods can also be used. The subtraction method is preferred.

The obtained base film side semi-finished product can be directly used for bonding to the surface film side semi-finished product, or can be attached to the release film and stored, and then bonded to the surface film side semi-finished product.

The film-side semi-finished product can be produced, for example, by applying an adhesive to the surface film. The crosslinking reaction in the applied adhesive can be carried out as necessary. In a preferred embodiment, the adhesive layer is semi-hardened.

The obtained film-side semi-finished product can be used as it is directly bonded to the base film side semi-finished product, or can be bonded to the base film side semi-finished product after being adhered to the release film.

The base film side semi-finished product and the surface film side semi-finished product are respectively stored in the form of a reel, and then bonded to form a printed circuit board. As the bonding method, any method can be used, for example, pressing or rolling can be used for lamination. Further, it is also possible to bond the two while heating by heating or pressing or using a heating roller device.

In the case of a reinforcing material side semi-finished product, for example, a reinforcing material which is soft and can be wound like a polyimide film, it is preferable to apply an adhesive to the reinforcing material. Further, for example, when a reinforcing plate which is hard and cannot be wound, such as a metal plate such as SUS or aluminum, or a glass fiber obtained by curing an epoxy resin, is used, an adhesive agent previously applied to a release substrate is used. It is preferable to carry out transfer coating and manufacture. Further, a crosslinking reaction in the applied adhesive can be carried out as necessary. In a preferred embodiment, the adhesive layer is semi-hardened.

The obtained reinforcing material side semi-finished product can be directly used for bonding to the back surface of the printed circuit board, or can be bonded to the release film and stored for use in bonding with the substrate film side semi-finished product.

The substrate film side semi-finished product, the surface film side semi-finished product, and the reinforcing material side semi-finished product are all laminates for printed circuit boards in the present invention. [Examples]

<Examples> Hereinafter, the present invention will be described in more detail by way of examples. However, the invention is not limited to the embodiments. The abbreviated parts in the examples and the comparative examples represent parts by mass.

(Physical evaluation method)

Acid value (A) component: a carboxyl group-containing polyolefin resin The acid value (equivalent/10 ⁶ g) of the carboxyl group-containing polyolefin resin (A) in the present invention is FT-IR (Shimadzu Corporation, FT-) IR8200PC), absorbance (I) of the stretching peak (1780 cm ^-1 ) of the carbonyl (C=O) bond of maleic anhydride, and absorbance of the peak (840 cm ^-1 ) specific to the polymer of the same row (II) The coefficient (f) obtained by the calibration curve prepared from the chloroform solution of maleic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) was calculated according to the following formula, and the calculated value was expressed by the equivalent (equivalent/10 ⁶ g) of the resin 1ton. Acid value = [absorbance (I) / absorbance (II) × (f) / molecular weight of maleic anhydride × 2 × 10 ⁴ ] Molecular weight of maleic anhydride: 98.06

Acid value (B) component: carboxyl group-containing styrene resin The acid value (equivalent/10 ⁶ g) of the carboxyl group-containing styrene resin (B) in the present invention is obtained by dissolving a carboxyl group-containing styrene resin in toluene, and The titration was carried out with phenolphthalein as an indicator in a methanolic sodium methoxide solution. It is represented by the equivalent (equivalent/10 ⁶ g) in the resin 1ton.

Weight average molecular weight (Mw) The weight average molecular weight in the present invention is manufactured by Shimadzu Corporation: GPC (gel permeation chromatography, hereinafter referred to as GPC, standard material: polystyrene resin, mobile phase: tetrahydrofuran, column) : Shodex KF-802+KF-804L+KF-806L, column temperature: 30 ° C, flow rate: 1.0 ml / min, detector: RI detector) measured value.

(1) Peeling strength (adhesiveness) The adhesive composition described below was applied to a polyimide film having a thickness of 12.5 μm (Kapika Co., Ltd., Apical (registered trademark), so that the thickness after drying was 25 μm. Or an LCP film (manufactured by Kuraray Co., Ltd., Vecstar (registered trademark)) having a thickness of 25 μm, and dried at 130 ° C for 3 minutes. The adhesive film (B-stage product) thus obtained was bonded to a rolled copper foil of 18 μm. The bonding was carried out so that the shiny side of the rolled copper foil was brought into contact with the adhesive, and pressed at 160 ° C under a pressure of 40 kgf / cm ² for 30 seconds. Then, it was heat-treated at 140 ° C for 4 hours to be hardened, and a sample for peel strength evaluation was obtained. The peel strength was stretched at 25 ° C, and a 90° peel test was performed at a tensile speed of 50 mm/min to measure the peel strength. This test is expressed as the strength at room temperature. <Evaluation Criteria> ◎: 1.0 N/mm or more ○: 0.8 N/mm or more and less than 1.0 N/mm △: 0.5 N/mm or more and less than 0.8 N/mm ×: less than 0.5 N/mm

(2) Dry solder heat resistance A sample was prepared by the same method as described above, and a 2.0 cm × 2.0 cm sample piece was dried at 120 ° C for 30 minutes, and flowed in a molten solder bath at each temperature for 1 minute, and the measurement was not performed. A temperature that causes a change in appearance such as a bulge. <Evaluation criteria> ◎: 310°C or more ○: 300°C or more and less than 310°C △: 290°C or more and less than 300°C ×: Not up to 290°C

(3) Humidification solder heat resistance A sample was prepared by the same method as described above, and a 2.0 cm × 2.0 cm sample piece was subjected to treatment at 40 ° C × 80 RH % × 72 hours, and flowed in a molten solder bath at each temperature for 1 minute. The temperature at which the appearance change such as bulging does not occur is measured. <Evaluation criteria> ◎: 260°C or higher ○: 260°C or less at 250°C or more △: 250°C or less at 240°C or less ×: 240°C or less

(4) Relative dielectric constant (ε _c ) and dielectric tangent (tan δ) The adhesive composition described later was applied to a glossy surface of an electrolytic copper foil having a thickness of 35 μm so that the thickness after drying and hardening became 25 μm. Dry at 130 ° C for 3 minutes. Then, it was heat-treated at 140 ° C for 4 hours to be hardened to obtain a copper-clad laminate for testing. On the hardened adhesive composition surface of the obtained copper-clad laminate for testing, a conductive dry silver-type conductive silver paste was applied by screen printing to a circular shape of 50 mm in diameter, and dried at 120 ° C for 30 minutes. This was hardened, and further, a parallel plate capacitor was obtained by using a conductive adhesive followed by a lead having a length of 30 mm in the center of a circle formed by the conductive silver paste. Using the PRECISION LCR meter HP-4284A, the electrostatic capacitance Cap and the loss factor D (dielectric tangent) of the obtained parallel plate capacitor were measured at a frequency of 1 MHz at 22 ° C, and the relative dielectric constant (ε _{c was} calculated according to the following formula). ). ε _c = (Cap × d) / (S × ε ₀ ) Here, Cap: electrostatic capacitance [F] d: dielectric layer thickness = 25 × 10 ^-6 [m] S: measured dielectric area = π ×(25 × 10 ^-3 ) ² ε ₀ : The dielectric constant of vacuum 8.854 × 10 ^-12 was evaluated for the relative dielectric constant and dielectric tangent obtained as follows. <Evaluation Criteria for Relative Dielectric Constant> ◎: 2.3 or less ○: more than 2.3 to 2.6 or less Δ: more than 2.6 to 3.0 or less ×: more than 3.0 <Evaluation criteria of dielectric tangent> ◎: 0.005 or less ○: more than 0.005 to 0.01 or less △: more than 0.01 to 0.02 or less ×: more than 0.02

(5) Flame retardancy The adhesive composition described later is applied to a polyimine film (manufactured by Kaneka Co., Ltd., Apical (registered trademark)) having a thickness of 25 μm so that the thickness after drying is 25 μm. Dry at 130 ° C for 3 minutes. Then, it was heat-treated at 140 ° C for 4 hours to be hardened to obtain a laminate. A sample piece was produced based on UL-94 using a laminate, and a burning test was performed based on the VTM method. <Evaluation Criteria> ○: VTM-0 condition is satisfied ×: VTM-1 or more, VTM-0 condition is not satisfied

(Polyurethane-containing polyolefin resin) [Production Example 1] 100 parts by mass of propylene-butene copolymer (TAFMER (registered trademark) XM7080) manufactured by Mitsui Chemicals Co., Ltd., and 150 mass of toluene were added to a 1 L autoclave. 19 parts by mass of maleic anhydride and 6 parts by mass of di-tert-butyl peroxide were heated to 140 ° C, and further stirred for 3 hours. Thereafter, the obtained reaction liquid was cooled, poured into a vessel containing a large amount of methyl ethyl ketone, and the resin was precipitated. Then, the acid-modified propylene-butene copolymer obtained by graft-polymerizing the resin-containing solution by grafting the maleic anhydride with (poly)maleic anhydride and a low molecular weight substance is separated and purified. Thereafter, it was dried under reduced pressure at 70 ° C for 5 hours to obtain a maleic anhydride-modified propylene-butene copolymer (CO-1, an acid value of 410 equivalents/10 ⁶ g, a weight average molecular weight of 60,000, and a Tm80). °C, △H35J/g).

[Production Example 2] A maleic anhydride-modified propylene-butene copolymer (CO-2, acid value) was obtained by the same method as in Production Example 1 except that the amount of the maleic anhydride was changed to 11 parts by mass. 224 equivalents/10 ⁶ g, weight average molecular weight 65,000, Tm 78 ° C, ΔH 25 J/g).

[Example 1] 80 parts by mass of a maleic anhydride-modified propylene-butene copolymer (CO-1) obtained in Production Example 1 was added to a 500 mL four-necked flask equipped with a water-cooled reflux condenser and a stirrer, and the like. 20 parts by mass of a carboxyl group-containing styrene resin (Tuftec (registered trademark) M1943), 450 parts by mass of methylcyclohexane, and 50 parts by mass of methyl ethyl ketone were heated to 80 ° C while stirring, and the mixture was stirred for 1 hour to be dissolved. To the solution obtained by cooling, 5 parts by mass of carbodiimide resin V-09 GB and 10 parts by mass of epoxy resin HP-7200 were blended to obtain a mixed solution. 60 parts by mass of the flame-retardant filler OP-935 was blended with the obtained mixed solution to obtain an adhesive composition. The blending amount, the bonding strength, the solder heat resistance, the electrical properties, and the flame retardancy are shown in Table 1.

[Examples 2 to 10] The carboxyl group-containing polyolefin resin, the carboxyl group-containing styrene resin, the carbodiimide resin, the epoxy resin, and the flame-retardant filler were changed as shown in Table 1, and the same procedure as in Example 1 was carried out. The methods of Examples 2 to 10 were carried out and changed to the respective blending amounts shown in Table 1. Next, the strength, solder heat resistance, electrical properties, and flame retardancy are shown in Table 1.

[Table 1]

[Comparative Examples 1 to 4] The carboxyl group-containing polyolefin resin, the carboxyl group-containing styrene resin, the carbodiimide resin, the epoxy resin, and the flame-retardant filler were changed as shown in Table 2, and the same as in Example 1. The methods of Comparative Examples 1 to 4 were changed to the respective blending amounts shown in Table 2. Next, the strength, solder heat resistance, electrical properties, and flame retardancy are shown in Table 2.

[Table 2]

The carboxyl group-containing polyolefin resin (A), the carboxyl group-containing styrene resin (B), the carbodiimide resin (C), the epoxy resin (D), and the flame-retardant filler (E) used in Tables 1 and 2 are as follows . Carboxyl group-containing styrene resin: Tuftec (registered trademark) M1913 (manufactured by Asahi Kasei Chemicals Co., Ltd.), acid value: 185 equivalents/10 ⁶ g Carboxyl group-containing styrene resin: Tuftec (registered trademark) M1943 (made by Asahi Kasei Chemicals Co., Ltd.), acid value 185 equivalents/10 ⁶ g carbodiimide resin: V-09GB (manufactured by Nisshinbo Chemical Co., Ltd.) Dicyclopentadiene type epoxy resin: HP-7200 (manufactured by DIC Corporation) Phosphorus-based flame retardant filler: EXOLIT (registered trademark) ) OP-935 (Clariant) Metal hydrate-based flame retardant filler: MGZ-3 (manufactured by Sigma Chemical Industry Co., Ltd.) Intumescent flame retardant filler: FP-2100JC (made by ADEKA) Phosphorus-based flame retardancy Non-filler: PX-200 (made by Daiba Chemical Co., Ltd.)

As is clear from Table 1, in Examples 1 to 10, the polyimide and the copper foil have excellent adhesion and solder heat resistance, and the liquid crystal polymer (LCP) and the copper foil also have excellent adhesion. , solder heat resistance. Further, the electrical properties of the adhesive composition were low in relative dielectric constant and dielectric tangent, and were good. It has achieved VTM-0 and is excellent in flame retardancy. In contrast, as seen from Table 2, in Comparative Example 1, the amount of the flame-retardant filler was small, and the flame retardancy was poor. In Comparative Example 2, the amount of the flame-retardant filler was large, and the adhesiveness and the moisturizing solder were inferior in heat resistance. In Comparative Example 3, an organic phosphorus-based flame retardant was blended and was excessively compatible with the adhesive, so that the adhesiveness and the moisturizing solder were inferior in heat resistance. In Comparative Example 4, only the carboxyl group-containing styrene resin was used, so the crosslinking density was low, and the humidifying solder was inferior in heat resistance. [Industrial use]

According to the present invention, it is possible to provide a laminate which is not only a conventional polyimide substrate, a polyethylene terephthalate film, a resin substrate having a low dielectric property such as LCP, or a metal substrate such as a copper foil. It also has high adhesion, high solder heat resistance, and low dielectric properties and flame retardancy. Based on the above characteristics, it is useful for flexible printed circuit board applications, particularly FPC applications requiring low dielectric properties (low relative dielectric constant, low dielectric tangent) in a high frequency region.

no

Claims (6)

A laminate (Z) comprising a resin substrate and a metal substrate laminated via an adhesive comprising a carboxyl group-containing polyolefin resin (A); characterized by: (1) an adhesive layer at a frequency of 1 MHz The relative dielectric constant (ε _c ) is 3.0 or less, (2) the dielectric tangent (tan δ) of the adhesive layer at a frequency of 1 MHz is 0.02 or less, and (3) the peel strength between the resin substrate and the metal substrate is 0.5. N/mm or more, (4) The heat resistance of the wet solder of the laminate (Z) is 240 ° C or higher, and (5) the laminate (X) obtained by removing the metal substrate from the laminate (Z) is In the UL-94 method, it is VTM-0. A laminate (X), which is a laminate of a resin substrate and a metal substrate, which is formed by laminating a layer of an adhesive including a carboxyl group-containing polyolefin resin (A). a laminate of the resin substrate; characterized in that: (1) the dielectric constant (ε _c ) of the adhesive layer at a frequency of 1 MHz is 3.0 or less, and (2) dielectric tangent of the adhesive layer at a frequency of 1 MHz (tan δ) is 0.02 or less, and (3) when a metal substrate is laminated on the adhesive layer of the laminate (X), the peel strength between the resin substrate and the metal substrate in the laminate is 0.5 N/mm. As described above, (4) when a metal substrate is laminated on the adhesive layer of the laminate (X), the heat resistance of the solder of the laminate is 240 ° C or higher, and (5) the laminate (X) is in the UL- In the 94 method, it is VTM-0. A laminate (Y), which is a laminate of a resin substrate and a metal substrate, which is formed by laminating a layer of an adhesive including a carboxyl group-containing polyolefin resin (A). laminate of the metal substrate; wherein: (1) adhesive layers relative dielectric constant to a frequency of 1MHz (ε _c) is 3.0 or less, (2) tangential to the adhesive layer of dielectric frequency of 1MHz (tan δ) is 0.02 or less, and (3) when a resin substrate is laminated on the adhesive layer of the laminate (Y), the peel strength between the resin substrate and the metal substrate in the laminate is 0.5 N/mm. (4) When the resin substrate is laminated on the adhesive layer of the laminate (Y), the heat resistance of the solder of the laminate is 240 ° C or higher, and (5) subsequent to the laminate (Y) The laminate layer of the resin substrate is laminated to form a laminate (Z), and then the laminate (X) obtained by removing the metal substrate is VTM-0 in the UL-94 method. An adhesive layer used as a laminate (Z) of a resin substrate and a metal substrate via a laminate layer comprising an adhesive layer of a carboxyl group-containing polyolefin resin (A); (1) The relative dielectric constant (ε _c ) of the adhesive layer at a frequency of 1 MHz is 3.0 or less, and (2) the dielectric tangent (tan δ) of the adhesive layer at a frequency of 1 MHz is 0.02 or less, and (3) When the resin substrate is laminated on one surface of the layer, and the metal substrate is laminated on the other surface, the peel strength between the resin substrate and the metal substrate in the laminate is 0.5 N/mm or more, and (4) When the resin substrate is laminated on one surface of the agent layer and the metal substrate is laminated on the other surface, the heat resistance of the solder of the laminate is 240 ° C or higher, and (5) the resin base is laminated on one side of the adhesive layer. The laminate (X) obtained after the material was VTM-0 in the UL-94 method. An adhesive sheet comprising the laminate (Z) of claim 1 of the patent application, the laminate (X) of claim 2, the laminate (Y) of claim 3, or For example, the adhesive layer of claim 4 is applied. A printed circuit board comprising a back sheet as in the fifth aspect of the patent application as a constituent element.