KR20220133748A - Flexible Metal Laminate and Method for Preparing the Same - Google Patents

Abstract

The present invention relates to a soft metal laminate comprising: an insulation laminate including an insulation layer including a liquid crystal polymer and an adhesive layer formed on at least one surface of the insulation layer; and a metal layer formed on the insulation laminate. The adhesive force between the insulation layer and the metal layer is 0.4 kN/m or higher. The dielectric constant of the insulation laminate at 15 GHz is 3.1 or lower, and the dielectric tangent of the insulation laminate is 0.0014 or lower. The tensile strength of the soft metal laminate is 200 MPa or higher. The soft metal laminate of the present invention has an excellent adhesive force between the insulation layer and the metal layer to suppress peeling in a drilling process for forming a hole in the metal layer to easily manufacture an FPCB, has a low dielectric property even in a high frequency band to reduce signal loss rates, and has excellent mechanical properties and bending resistance to effectively manufacture an FPCB.

Description

Flexible Metal Laminate and Method for Preparing the Same

The present invention relates to a flexible metal laminate and a method for manufacturing the same, and more particularly, the delamination phenomenon is suppressed during a drilling process for forming a hole in a metal layer, so that FPCB fabrication is easy, the signal loss rate is reduced even in a high frequency band, and the mechanical The present invention relates to a flexible metal laminate having excellent properties and resistance to bending, and a method for manufacturing the same.

Recently, the communication and vehicle-mounted markets are moving from 4G to 5G, and accordingly, high performance of various parts is required. In the case of 5G, the frequency used for communication is required from 4G up to 3.5GHz to 5G up to 28GHz, and for in-vehicle use up to 70GHz. Accordingly, low dielectric properties are required. Accordingly, various industries are developing materials for lowering dielectric properties.

Flexible metal laminates are mainly used as substrates for flexible printed circuit boards (FPCBs), and other surface heating element electromagnetic shielding materials, flat cables, packaging materials, and the like. Among these flexible metal laminates, the flexible copper foil laminate is mainly composed of a polyimide layer and a copper foil layer, and may be divided into an adhesive type and a non-adhesive type depending on whether an epoxy adhesive layer exists between the polyimide layer and the copper foil layer.

Korean Patent Laid-Open Publication No. 10-2013-0027442 discloses a first metal layer; a first polyimide layer; a polyimide layer in which a fluororesin is dispersed formed on the first polyimide layer; and a second polyimide layer formed on the polyimide layer in which the fluororesin is dispersed; in the polyimide layer in which the fluororesin is dispersed, the content per unit volume of the fluororesin is the total amount from the surface of the polyimide layer. It has been described for a flexible metal laminate with improved adhesion and dielectric properties with a metal layer by being larger at a depth of 40 to 60% than at a depth of 5 to 10% of the thickness, but polyimide has a high dielectric constant of its own. There is a problem in that it is difficult to satisfy the required high-speed level.

Accordingly, there is a demand for the development of a printed circuit board using an insulator having a lower dielectric constant and a dielectric loss coefficient than that of a conventional polyimide insulator.

In this regard, a laminate is known in which a film made of a liquid crystal polymer and a metal layer capable of constituting a circuit (conductor pattern) are laminated via an adhesive layer. This laminate has the advantage that the FPCB can be formed by multilayering, and in that case, the wiring density can be increased, so that the operation is wide.

However, since the film made of the liquid crystal polymer does not have sufficient adhesion to the metal layer, there is a problem in that a peeling phenomenon occurs during a drilling process for forming a hole in the metal layer for manufacturing an FPCB.

On the other hand, there is a demand for the development of a flexible metal laminate having excellent mechanical properties and bending resistance so that the FPCB can be manufactured more easily.

Republic of Korea Patent Publication No. 10-2013-0027442

One object of the present invention is to provide a flexible metal laminate with excellent mechanical properties and flex resistance, which is easy to manufacture FPCB because peeling is suppressed during a drilling process for forming a hole in a metal layer, a signal loss rate is reduced even in a high frequency band, and excellent mechanical properties and bending resistance will be.

Another object of the present invention is to provide a method for manufacturing the flexible metal laminate.

Another object of the present invention is to provide a printed wiring board using the flexible metal laminate.

On the other hand, the present invention provides an insulating laminate comprising an insulating layer comprising a liquid crystal polymer and an adhesive layer formed on at least one surface of the insulating layer, and a flexible metal laminate comprising a metal layer formed on the insulating laminate,

The adhesion between the insulating layer and the metal layer is 0.4 kN / m or more,

The dielectric constant at 15 GHz of the insulating laminate is 3.1 or less and the dielectric loss tangent is 0.0014 or less,

It provides a flexible metal laminate having a tensile strength of 200 MPa or more of the flexible metal laminate.

In the flexible metal laminate according to the exemplary embodiment of the present invention, an elongation in the MD direction of the insulating layer may be 13% or more, and an elongation in a TD direction may be 16% or more.

When the flexible metal laminate according to an embodiment of the present invention repeats the operation of bending and unfolding the flexible metal laminate at a radius of 1R (R = 1mm) in the MD and TD directions at 180°, disconnection during resistance measurement The number of repetitions performed may be 210 or more.

The flexible metal laminate according to an embodiment of the present invention may be manufactured by heat-treating the insulating layer including the liquid crystal polymer, forming an adhesive layer, and bonding the metal layer.

In an embodiment of the present invention, the heat treatment of the insulating layer may be performed at a temperature of T _m to T _m +10°C (T _m is the melting point of the liquid crystal polymer) for 60 to 360 minutes.

In one embodiment of the present invention, the adhesive layer may be formed from an adhesive composition including an acid-modified polyolefin resin.

On the other hand, the present invention

heat-treating the insulating layer including the liquid crystal polymer;

forming an adhesive layer on at least one surface of the heat-treated insulating layer to obtain an insulating laminate; and

It provides a method of manufacturing a flexible metal laminate comprising bonding a metal layer on the insulating laminate.

In one embodiment of the present invention, after the step of bonding the metal layer, the adhesive force between the insulating layer and the metal layer is 0.4 kN/m or more, the dielectric constant at 15 GHz of the insulating laminate is 3.1 or less, and the dielectric loss tangent is 0.0014 or less, and , the tensile strength of the flexible metal laminate may be 200 MPa or more.

In one embodiment of the present invention, after the step of bonding the metal layer, bending and unfolding the flexible metal laminate at a radius of 1R (R = 1mm) in the MD and TD directions at 180° condition is repeated. The number of repetitions of disconnection during resistance measurement may be 210 or more.

In an embodiment of the present invention, the heat treatment of the insulating layer may be performed at a temperature of T _m to T _m +10°C (T _m is the melting point of the liquid crystal polymer) for 60 to 360 minutes.

In one embodiment of the present invention, the heat treatment of the insulating layer may be performed on a polyimide film support.

In one embodiment of the present invention, the MD direction elongation of the heat-treated insulating layer may be 13% or more, TD direction elongation may be 16% or more.

On the other hand, the present invention provides a printed wiring board using the flexible metal laminate.

The flexible metal laminate of the present invention has excellent adhesion between the insulating layer and the metal layer, and thus the peeling phenomenon is suppressed during the drilling process for forming a hole in the metal layer, so that the FPCB is easy to manufacture, and it has low dielectric properties even in a high frequency band. The loss ratio is lowered, and the mechanical properties and bending resistance are excellent, making it possible to manufacture FPCBs smoothly.

1 is a schematic cross-sectional view of a flexible metal laminate according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail.

An embodiment of the present invention provides an insulating laminate including an insulating layer containing a liquid crystal polymer and an adhesive layer formed on at least one surface of the insulating layer, and a flexible metal laminate including a metal layer formed on the insulating laminate,

The adhesion between the insulating layer and the metal layer is 0.4 kN / m or more,

The dielectric constant at 15 GHz of the insulating laminate is 3.1 or less and the dielectric loss tangent is 0.0014 or less,

It relates to a flexible metal laminate having a tensile strength of 200 MPa or more of the flexible metal laminate.

As described above, the flexible metal laminate according to an embodiment of the present invention uses an insulating layer including a liquid crystal polymer as an insulating layer, and has a structure in which the insulating layer is bonded to the metal layer through an adhesive layer, and the insulating layer and the The adhesion between the metal layers is controlled to 0.4 kN/m or more, the dielectric constant at 15 GHz of the insulating laminate is controlled to 3.1 or less, and the dielectric loss tangent is controlled to 0.0014 or less, and the tensile strength of the flexible metal laminate is controlled to 200 MPa or more. During the drilling process for forming a hole in the metal layer, the peeling phenomenon is suppressed, so that the FPCB can be easily manufactured, the signal loss rate can be reduced even in the high frequency band, and the FPCB can be manufactured smoothly.

The adhesion between the insulating layer and the metal layer means the bonding force between the insulating layer and the metal layer, and may be measured by the method described in Experimental Examples to be described later.

As described above, the adhesion between the insulating layer and the metal layer may be 0.4 kN/m or more, for example, 0.4 to 1.5 kN/m, preferably 0.6 kN/m or more, and more preferably 1.0 kN/m or more.

In one embodiment of the present invention, when the adhesion between the insulating layer and the metal layer is less than 0.4 kN/m, a peeling phenomenon may occur during a drilling process for forming a hole in the metal layer.

The dielectric constant (dielectric constant) is a physical unit indicating the effect of a medium between the charges on the electric field when an electric field acts between the charges, it can also be viewed as the amount of charge that the medium can store.

The dielectric constant at 15 GHz of the insulating laminate is a value measured at a frequency of 15 GHz according to the method described in Experimental Examples to be described later.

The dielectric constant at 15 GHz of the insulating laminate may be 3.1 or less as described above, for example, more than 1 and 3.1 or less. If the dielectric constant at 15 GHz of the insulating laminate exceeds 3.1, the signal loss rate may increase by lowering the antenna gain value in a high frequency band such as 15 GHz, or may affect the driving of other devices such as a touch sensor.

The dielectric tangent (dielectric tangent) is a unit representing the ratio of power loss generated when an AC voltage is applied to the dielectric, and is generally expressed as tangent delta (tangent δ).

The dielectric loss tangent at 15 GHz of the insulating laminate is a value measured at a frequency of 15 GHz according to the method described in Experimental Examples to be described later.

The dielectric loss tangent at 15 GHz of the insulating laminate may be 0.0014 or less as described above, for example, more than 0 and 0.0014 or less. If the dielectric loss tangent at 15 GHz of the insulating laminate exceeds 0.0014, the signal loss rate may increase by lowering the antenna gain value in a high frequency band such as 15 GHz, or may affect the driving of other devices such as a touch sensor.

The tensile strength is a force representing the strength of a material, and is defined as a value obtained by dividing the maximum load that the material withstands when pulled until fracture by the cross-sectional area of the material.

The tensile strength of the flexible metal laminate can be measured by performing a tensile test on a flexible metal laminate having a width of 25 mm with a gage distance of 50 mm before stretching, and more specifically, according to the method described in Experimental Examples to be described later. can be measured.

The tensile strength of the flexible metal laminate may be 200 MPa or more, for example, 200 to 400 MPa, preferably 200 to 300 MPa, as described above. If the tensile strength of the flexible metal laminate is less than 200 MPa, bending resistance may be deteriorated, and if it exceeds 400 MPa, cracking may occur due to torsion and external impact.

In the flexible metal laminate according to the exemplary embodiment of the present invention, an elongation in the MD direction of the insulating layer may be 13% or more, and an elongation in a TD direction may be 16% or more.

Elongation is the degree of ductility of a material measured in a tensile test, also called elongation. Elongation is defined as the value obtained by dividing the increase in gage distance measured after the specimen is stretched and fractured by the gage distance before stretching.

The elongation in the MD direction and the TD direction of the insulating layer can be measured by performing tensile tests in the MD and TD directions, respectively, in the MD and TD directions with a gage distance of 50 mm before stretching for an insulating layer having a width of 15 mm, more specifically described later It can be measured according to the method described in the experimental example.

The MD direction elongation of the insulating layer may be 13% or more, for example, 13 to 30%, preferably 20 to 30%. If the elongation in the MD direction of the insulating layer is less than 13%, the flex resistance of the flexible metal laminate and/or the FPCB manufactured using the same may be deteriorated, and if it exceeds 30%, it may be difficult to control the thickness uniformity and tension of the laminate.

The TD direction elongation of the insulating layer may be 16% or more, for example, 16 to 30%, preferably 20 to 30%. If the elongation in the TD direction of the insulating layer is less than 16%, the flex resistance of the flexible metal laminate and/or the FPCB manufactured using the same may be deteriorated, and if it exceeds 30%, it may be difficult to control the thickness uniformity and tension of the laminate.

When the flexible metal laminate according to an embodiment of the present invention repeats the operation of bending and unfolding the flexible metal laminate at a radius of 1R (R = 1mm) in the MD and TD directions at 180°, disconnection during resistance measurement The number of repetitions may be 210 or more, for example, 210 to 400, specifically 210 to 300. If the number of repetitions of bending of the flexible metal laminate is less than 210, circuit breakage may occur due to deterioration in bending resistance.

1 is a schematic cross-sectional view of a flexible metal laminate according to an embodiment of the present invention.

1, the flexible metal laminate according to an embodiment of the present invention is an insulating laminate including a first adhesive layer 110 and a second adhesive layer 120 formed on both surfaces of the insulating layer 100 ( 10), the first metal layer 20 and the second metal layer 30 have a stacked structure. 1 shows a structure in which an adhesive layer is formed on both sides of the insulating layer 100 and a metal layer is laminated on both sides of the insulating laminate 10 , but a metal layer may be laminated only on one side of the insulating laminate 10 . .

In one embodiment of the present invention, the insulating layer includes a liquid crystal polymer.

Specifically, the insulating layer may include a cured product of a liquid crystal polymer composition including a liquid crystal polymer (LCP).

The liquid crystal polymer refers to a thermoplastic plastic exhibiting nematic crystallinity upon melting.

Since the liquid crystal polymer has a low dielectric constant and a low dielectric loss tangent, when applied to a printed wiring board, there is an advantage that a signal transmission loss can be minimized even at a high transmission speed. In addition, since the liquid crystal polymer has low water absorption and low moisture absorption, there is an advantage in that the change in electrical properties is small.

As the liquid crystal polymer, those used in the art may be used without particular limitation, and may preferably be liquid crystal polyester.

The liquid crystalline polyester may be a liquid crystalline polyester amide, a liquid crystalline polyester ether, a liquid crystalline polyester carbonate, or a liquid crystalline polyester imide. The liquid crystalline polyester is preferably a wholly aromatic liquid crystalline polyester made using only an aromatic compound as a raw material monomer.

Examples of the liquid crystalline polyester include polymerization (polycondensation) of at least one compound selected from the group consisting of aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol, aromatic hydroxyamine and aromatic diamine. liquid crystalline polyester; liquid crystal polyester in which a plurality of types of aromatic hydroxycarboxylic acids are polymerized; liquid crystal polyester in which aromatic dicarboxylic acid and at least one compound selected from the group consisting of aromatic diol, aromatic hydroxylamine and aromatic diamine are polymerized; And liquid-crystalline polyester in which polyester, such as polyethylene terephthalate, and aromatic hydroxycarboxylic acid are superposed|polymerized is mentioned. Here, the aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol, aromatic hydroxyamine, and aromatic diamine may each independently represent a part or all of the aromatic diamine and may be a polymerizable derivative thereof.

Examples of the polymerizable derivative of a compound having a carboxyl group such as aromatic hydroxycarboxylic acid and aromatic dicarboxylic acid include a derivative obtained by converting a carboxyl group into an alkoxycarbonyl group or an aryloxycarbonyl group (also referred to as an ester), a carboxyl group into a haloformyl group derivatives formed by conversion (also referred to as acid halide) and derivatives formed by converting a carboxyl group to an acyloxycarbonyl group (also referred to as acid anhydrides) are mentioned.

Examples of polymerizable derivatives of compounds having a hydroxyl group, such as aromatic hydroxycarboxylic acids, aromatic diols and aromatic hydroxylamines, include derivatives formed by acylating a hydroxyl group to convert it to an acyloxyl group (also referred to as an acylate). ) can be mentioned. Examples of the polymerizable derivative of a compound having an amino group such as aromatic hydroxylamine and aromatic diamine include a derivative (also referred to as an acylate) formed by acylating an amino group to convert it to an acylamino group.

For example, the liquid crystalline polyester may include at least one repeating unit derived from an aromatic diamine, a repeating unit derived from an aromatic amine having a hydroxyl group, or a repeating unit derived from an aromatic amino acid.

When the liquid crystalline polyester includes the repeating units, it may be included in an amount of 10 to 35 mol% based on 100 mol% of all repeating units constituting the liquid crystalline polyester. This may mean that, when the liquid crystalline polyester includes two or more kinds of the repeating units, the mol% of the total of the two or more kinds of repeating units is 10 to 35 mol%.

For example, the liquid crystalline polyester may include a repeating unit derived from an aromatic hydroxycarboxylic acid; repeating units derived from aromatic dicarboxylic acids; and a repeating unit derived from an aromatic diamine, an aromatic amine having a hydroxyl group, or an aromatic amino acid. Specifically, the liquid crystalline polyester may include repeating units represented by the following Chemical Formulas 1 to 3, and their content is from 30 to 100 mol% of all repeating units constituting the liquid crystalline polyester, respectively. 80 mol%, 10-35 mol% and 10-35 mol%.

[Formula 1]

-O-Ar ₁ -CO-

(In Formula 1,

Ar ₁ is 1,4-phenylene, 2,6-naphthalene, or 4,4'-biphenylene.)

[Formula 2]

-CO-Ar ₂ -CO-

(In Formula 2,

Ar ₂ is 1,4-phenylene, 1,3-phenylene or 2,6-naphthalene.)

[Formula 3]

-X-Ar ₃ -Y-

(In Formula 3,

X is NH;

Y is O, NH or C=O,

Ar ₃ is 1,4-phenylene or 1,3-phenylene.)

The liquid crystalline polyester including the repeating unit is a derivative of the above aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, aromatic diamine, aromatic amine or aromatic amino acid having a hydroxyl group, such as a derivative having an ester-forming property. It may be prepared using an ester-forming derivative, but is not limited thereto.

As an ester-forming derivative of a compound having a carboxylic acid group, for example, a group having a high reaction activity such as an acid chloride or an acid anhydride so that the carboxyl group promotes a reaction to form a polyester, and the carboxyl group is an ester In order to produce|generate polyester by the exchange reaction, the thing which forms ester with alcohol, ethylene glycol, etc. are mentioned.

The ester-forming derivative of the compound having an aromatic hydroxyl group may include, for example, those in which the aromatic hydroxyl group forms an ester with carboxylic acids to produce polyester by transesterification.

The ester-forming derivative of the compound having an amino group may include, for example, one in which the amino group forms an ester with carboxylic acids to produce polyester by transesterification.

The repeating unit represented by Formula 1 is specifically, p-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, 4-hydroxy-4'-biphenylcarboxylic acid, and 6-hydroxy-2-naphthalene. and repeating units derived from at least one selected from the group consisting of carboxylic acids.

The content of the repeating unit represented by Formula 1 is not limited thereto, but based on 100 mol% of the total repeating units constituting the liquid crystalline polyester including the same, 30 to 80 mol%, preferably 40 to 70 mol% , more preferably 45 to 65 mol%. When it exceeds the above range, solubility in a solvent may decrease, and when included below the above range, it may be somewhat difficult to exhibit liquid crystallinity.

The repeating unit represented by Formula 2 is specifically, a repeating unit derived from at least one selected from the group consisting of terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, and 1,3-benzenedicarboxylic acid. and the like.

The content of the repeating unit represented by Formula 2 is not limited thereto, but based on 100 mol% of the total repeating units constituting the liquid crystalline polyester including the same, 10 to 35 mol%, preferably 15 to 30 mol% , more preferably 17.5 to 27.5 mol% may be included. When the above content is satisfied, solubility in a solvent may be further improved.

The repeating unit represented by Formula 3 is specifically, a repeating unit derived from at least one selected from the group consisting of 3-aminophenol, 4-aminophenol, 1,4-phenylenediamine and 1.3-phenylenediamine. can be heard

The content of the repeating unit represented by Formula 3 is not limited thereto, but based on 100 mol% of the total repeating units constituting the liquid crystalline polyester including the same, 10 to 35 mol%, preferably 15 to 30 mol% , more preferably 17.5 to 27.5 mol%. When it exceeds the above range, liquid crystallinity may be reduced, and when included below the above range, solubility in a solvent may be somewhat reduced.

The polyester may further include fillers, additives, or one or more thermoplastic resins commonly used in the art.

The fillers include, for example, organic fillers such as epoxy resin powder, melamine resin powder, urea resin powder, benzoguanamine resin powder and styrene resin; or inorganic fillers such as silica, alumina, titanium oxide, zirconia, kaolin, calcium carbonate and calcium phosphate; and the like, and the additive may include, but is not limited to, a coupling agent, an anti-settling agent, a UV absorber, a heat stabilizer, and the like.

The thermoplastic resin is, for example, polypropylene, polyamide, polyphenylene sulfide, polyether ketone, polycarbonate, polyether sulfone, polyphenyl ether and modified polymers thereof, and polyether imide, glycidyl methacryl and an elastomer such as a copolymer of lactate and ethylene, but is not limited thereto.

The liquid crystal polymer described above may be used in a dispersed form in a solvent, and the solvent used in this case may be, for example, an aprotic solvent, specifically 1-chlorobutane, chlorobenzene, 1,1-dichloroethane, halogen solvents such as 1,2-dichloroethane, chloroform and 1,1,2,2-tetrachloroethane; etheric solvents such as diethyl ether, tetrahydrofuran and 1,4-dioxane; ketone solvents such as acetone and cyclohexanone; ester solvents such as ethyl acetate; lactone solvents such as γ-butyrolactone; carbonate solvents such as ethylene carbonate and propylene carbonate; amine solvents such as triethylamine and pyridine; nitrile solvents such as acetonitrile and succinonitrile; amide solvents such as N,N'-dimethyl formamide, N,N'-dimethyl acetoamide, tetramethylurea and N-methylpyrrolidone; nitro solvents such as nitromethane and nitrobenzene; sulfide solvents such as dimethylsulfoxide and sulfolane; and phosphate solvents such as hexamethylphosphoramide and tri-n-butyl phosphate. Preferably, in consideration of the environmental impact, a solvent containing no halogen atom may be used, and from the viewpoint of solubility, dipole Solvents having moments of 3 to 5 can be used. Examples of the solvent having a dipole moment of 3 to 5 include amide solvents such as N,N'-dimethyl formamide, N,N'-dimethyl acetoamide, tetramethylurea and N-methylpyrrolidone, and γ -Lactone solvents such as butyrolactone, and the like, preferably N,N'-dimethyl formamide, N,N'-dimethyl acetoamide and N-methylpyrrolidone, etc., but are limited thereto it is not

According to an embodiment of the present invention, the content of the liquid crystal polymer may be included in an amount of 5 to 50% by weight, preferably 10 to 40% by weight, more preferably 20 to 50% by weight, based on 100% by weight of the total solid content in the composition. It may be included in 40% by weight.

If the content of the liquid crystal polymer is less than the above range, there may be problems in processability such as the composition flowing down during coating of the composition including the same. may occur.

The liquid crystal polymer composition may further include an inorganic filler or a surfactant in addition to the above-mentioned components.

The kind of the inorganic filler may be used without particular limitation to those used in the art, for example, silica, silica nitride, alumina, aluminum nitride, boron nitride, etc., and preferably silica filler, For example, natural silica, synthetic silica, fused silica, etc. may be used, and these may be used alone or in combination of two or more. As such, when the liquid crystal polymer composition of the present invention further includes an inorganic filler, it is possible to significantly reduce the coefficient of thermal expansion due to the fluorine-based resin, so that durability can be improved.

The average particle diameter of the inorganic filler is not particularly limited in the present invention, but may be, for example, 0.05 to 20 µm, preferably 0.1 to 10 µm, and more preferably 0.1 to 5 µm. When the average particle diameter of the inorganic filler is less than the above range, the surface area of the inorganic filler increases, which may cause a problem in that the physical properties of the liquid crystal polymer layer prepared therefrom are slightly reduced or the amount of additives such as a dispersant is slightly increased, When it exceeds, the surface properties of the liquid crystal polymer layer may be lowered or the dispersibility of the composition for forming the polymer layer may be slightly lowered.

According to an embodiment of the present invention, the inorganic filler may be included in an amount of 20 to 40% by weight based on 100% by weight of the total solid content in the composition. If the content of the inorganic filler is less than 20% by weight, the coefficient of thermal expansion may increase, and if the content of the inorganic filler is more than 40% by weight, the dielectric properties may be reduced.

In one embodiment of the present invention, the type of the surfactant is not particularly limited in the present invention, and those used in the art may be used without limitation. When the liquid crystal polymer composition includes a surfactant, there is an advantage in that the dispersibility of each component in the composition can be further improved.

The surfactant may include, for example, a fluorine-based surfactant or a silicone-based surfactant, and the fluorine-based surfactant may be preferably a nonionic organic surfactant. The fluorine-based surfactant is, for example, commercially available AGC-71L, S-381, S-383, S-393, SC-101, Sc-105, KH-40, SA-100, S-611, S -386, S-221, S-231, S-243, S-420, S-651, Megapiece F-470, F-471, F-475, F-482 and/or from Dainippon Ink Chemicals High School F-489 etc. are mentioned, For example, the said silicone surfactant includes DC3PA, DC7PA, SH11PA, SH21PA, and/or SH8400 of Dow Corning Toray Silicones as a commercial item. And TSF-4440, TSF-4300, TSF-4445, TSF-4446, TSF-4460, and/or TSF-4452 manufactured by GE Toshiba Silicone, etc., may be used alone or in combination of two or more. .

In one embodiment of the present invention, the insulating layer may have a single-layer or multi-layer structure.

The thickness of the insulating layer may be 5 to 100 μm, preferably 5 to 75 μm, and more preferably 8 to 50 μm. If the thickness of the insulating layer is less than the above range, there may be a problem that the transmission loss rate is slightly increased in the high frequency region, and if it exceeds the above range, it may be difficult to thin the product.

The flexible metal laminate may be manufactured by heat-treating the insulating layer including the liquid crystal polymer, forming an adhesive layer, and bonding the metal layer.

Through the heat treatment of the insulating layer, the adhesion between the insulating layer and the metal layer, the dielectric constant and dielectric loss tangent at 15 GHz of the insulating laminate, the elongation in the MD and TD directions of the insulating layer, and the tensile strength and bending resistance of the flexible metal laminate It can be adjusted in the above range.

The heat treatment of the insulating layer may be performed at a temperature of T _m to T _m +10° C. (T _m is the melting point of the liquid crystal polymer), for example, 293 to 303° C. for 60 to 360 minutes.

When the heat treatment temperature of the insulating layer is less than T _m , the adhesion between the insulating layer and the metal layer, the dielectric constant and dielectric loss tangent at 15 GHz of the insulating laminate, the elongation in the MD and TD directions of the insulating layer, and the tensile strength of the ductile metal laminate It may be difficult to adjust the flex resistance within the above range, and if T _m exceeds +10℃, blisters occur in the insulating layer and the tensile strength is lowered, or the elongation in the MD and TD directions of the insulating layer is adjusted within the above range. It can be difficult to do.

If the heat treatment time of the insulating layer is less than 60 minutes, the adhesion between the insulating layer and the metal layer, the dielectric constant and dielectric loss tangent at 15 GHz of the insulating laminate, the elongation in the MD and TD directions of the insulating layer, and the tensile strength of the ductile metal laminate It may be difficult to simultaneously control the flex resistance within the above range, and if it exceeds 360 minutes, blistering occurs in the insulating layer to lower the tensile strength, or it is difficult to adjust the elongation in the MD and TD directions of the insulating layer within the above range. can

In one embodiment of the present invention, the first adhesive layer 110 and the second adhesive layer 120 may be each independently formed from an adhesive composition including an acid-modified polyolefin resin.

The acid-modified polyolefin resin is a polyolefin resin modified with an acid-modified group such as a carboxyl group or an acid anhydride group.

More specifically, the acid-modified polyolefin resin is preferably obtained by grafting at least one of α,β-unsaturated carboxylic acid and an acid anhydride thereof to a polyolefin resin. Polyolefin resin refers to a polymer mainly having a hydrocarbon backbone, such as homopolymerization of olefin monomers exemplified by ethylene, propylene, butene, butadiene, isoprene, etc., or copolymerization with other monomers, and a hydride or halide of the obtained polymer. . That is, the acid-modified polyolefin resin is preferably obtained by grafting at least one of α,β-unsaturated carboxylic acid and its acid anhydride to at least one of polyethylene, polypropylene, and propylene-α-olefin copolymer. .

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

Examples of at least one of α,β-unsaturated carboxylic acids and their acid anhydrides include maleic acid, itaconic acid, citraconic acid, and acid anhydrides thereof. Among these, an acid anhydride is preferable and maleic anhydride is more preferable.

For example, as the acid-modified polyolefin resin, maleic anhydride-modified polypropylene, maleic anhydride-modified propylene-ethylene copolymer, maleic anhydride-modified propylene-butene copolymer, maleic anhydride-modified propylene-ethylene-butene copolymer, etc. These are mentioned, These acid-modified polyolefin resin can be used 1 type or in combination of 2 or more types.

The acid value of the acid-modified polyolefin resin may be 100 to 1000 equivalents/10 ⁶ g, and the weight average molecular weight (Mw) is preferably in the range of 10,000 to 180,000.

As a method for producing the acid-modified polyolefin resin, for example, a radical graft reaction, that is, a radical generating agent is used to generate a radical species with respect to a polymer serving as a main chain, and the radical species is used as a polymerization initiation point to form an unsaturated carboxylic acid and an acid anhydride. and a reaction in which graft polymerization is carried out.

Although it does not specifically limit as said radical generator, It is preferable to use organic peroxide, azonitrile, etc. Examples of organic peroxides include di-tert-butylperoxyphthalate, tert-butylhydroperoxide, dicumylperoxide, benzoylperoxide, tert-butylperoxybenzoate, tert-butylperoxy-2-ethylhexano. ate, tert-butyl peroxypivalate, methyl ethyl ketone peroxide, di-tert-butyl peroxide, lauroyl peroxide, and the like. Examples of azonitriles include azobisisobutyronitrile and azobisisopro. Pionitrile etc. are mentioned.

The adhesive composition may further include, in addition to the acid-modified polyolefin resin, a carboxyl group-containing styrene resin, a polyphenylene ether resin, an epoxy resin, and the like.

The carboxyl group-containing styrene resin can increase the adhesiveness of the adhesive composition, and an aromatic vinyl compound alone or a copolymer mainly having a block and/or random structure of an aromatic vinyl compound and a conjugated diene compound, or a hydrogenated product thereof Those modified with an acid are preferred. Although it does not specifically limit as said aromatic vinyl compound, For example, styrene, t-butylstyrene, alpha-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylstyrene, N,N-diethyl-p- aminoethylstyrene, vinyltoluene, p-tert-butylstyrene, etc. are mentioned. Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethyl-1,3-butadiene. Specific examples of copolymers of these aromatic vinyl compounds and conjugated diene compounds include styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene/ A propylene-styrene block copolymer (SEEPS) etc. are mentioned.

Modification of a carboxyl group-containing styrene resin can be performed by copolymerizing an unsaturated carboxylic acid at the time of superposition|polymerization of a styrene resin, for example. It can also be carried out by heating and kneading a styrene resin and an unsaturated carboxylic acid in the presence of an organic peroxide. It does not specifically limit as unsaturated carboxylic acid, Acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, maleic anhydride, itaconic anhydride, fumaric acid anhydride, etc. are mentioned.

The acid value of the carboxyl group-containing styrene resin may be 10 to 1000 equivalents/10 ⁶ g.

The content of the carboxyl group-containing styrene resin is preferably 95 to 5 parts by weight based on 100 parts by weight of the acid-modified polyolefin resin.

The polyphenylene ether resin is a polymer including a substituted or unsubstituted phenoxy group as a repeating unit, and serves to improve the heat resistance of the adhesive composition.

As a substituent of the phenoxy group, a C ₁ -C ₆ alkyl group, a C ₂ -C ₆ alkenyl group, a C ₂ -C ₆ alkynyl group, an aryl group, an aralkyl group, or a C ₁ -C ₆ alkoxy group is selected. for example.

As used herein, C ₁ -C ₆ Alkyl group refers to a linear or branched monovalent hydrocarbon having 1 to 6 carbon atoms, for example, methyl, ethyl, n-propyl, i-propyl, n-butyl , i-butyl, t-butyl, n-pentyl, n-hexyl, and the like.

As used herein, the C ₂ -C ₆ alkenyl group refers to a straight-chain or branched unsaturated hydrocarbon having 2 to 6 carbon atoms having one or more carbon-carbon double bonds, for example, ethyleneyl, propenyl, Tenyl, pentenyl, and the like are included, but are not limited thereto.

As used herein, the C ₂ -C ₆ alkynyl group refers to a straight-chain or branched unsaturated hydrocarbon having 2 to 6 carbon atoms having at least one carbon-carbon triple bond, and acetylenyl, propynyl, butynyl, etc. included, but not limited to.

Aryl groups as used herein include both aromatic groups and heteroaromatic groups and partially reduced derivatives thereof. The aromatic group is a 5-membered to 15-membered simple or fused cyclic group, and the heteroaromatic group refers to an aromatic group containing at least one oxygen, sulfur or nitrogen. Examples of representative aryl groups include phenyl, naphthyl, pyridinyl, furanyl, thiophenyl, indolyl, quinolinyl, imidazolinyl, Oxazolyl, thiazolyl, tetrahydronaphthyl, and the like, but are not limited thereto.

As used herein, the aralkyl group (aralkyl group) refers to a composite group formed by substituting an aryl group (aromatic hydrocarbon group) at the carbon of the alkyl group, and includes, for example, benzyl, phenethyl, etc., but is not limited thereto.

As used herein, the C ₁ -C ₆ alkoxy group refers to a straight-chain or branched alkoxy group having 1 to 6 carbon atoms, and includes, but is not limited to, methoxy, ethoxy, n-propanoxy, and the like.

The polyphenylene ether resin may include, for example, poly( p -phenylene oxide).

The polyphenylene ether resin may have a number average molecular weight (Mn) of 500 to 30,000, preferably 500 to 3,000.

The content of the polyphenylene ether resin may be 0.05 to 200 parts by weight, preferably 1 to 50 parts by weight, based on 100 parts by weight of the acid-modified polyolefin resin.

The said epoxy resin is not specifically limited as long as it has a glycidyl group in a molecule|numerator as a hardening|curing agent, It can be used. In particular, the epoxy resin preferably has two or more glycidyl groups in the molecule. Specifically, the epoxy resin is a biphenyl type epoxy resin, a naphthalene type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a novolak type epoxy resin, an alicyclic epoxy resin, a dicyclopentadiene type epoxy resin, tetra From the group consisting of glycidyldiaminodiphenylmethane, triglycidylparaaminophenol, tetraglycidylbisaminomethylcyclohexanone, N,N,N',N'-tetraglycidyl-m-xylenediamine At least one selected may be used. Preferably, the said epoxy resin is a bisphenol A type epoxy resin, a novolak type epoxy resin, or a dicyclopentadiene type epoxy resin.

The content of the epoxy resin may be 1 to 30 parts by weight based on 100 parts by weight of the total amount of the acid-modified polyolefin resin, the carboxyl group-containing styrene resin, and the polyphenylene ether resin.

The adhesive composition may further include an organic solvent. The organic solvent is not particularly limited as long as it dissolves the components in the adhesive composition. For example, the organic solvent may be an aromatic hydrocarbon such as benzene, toluene or xylene, an aliphatic hydrocarbon such as hexane, heptane, octane or decane, an alicyclic hydrocarbon such as cyclohexane, cyclohexene, methylcyclohexane or ethylcyclohexane, or trichloro Halogenated hydrocarbons such as ethylene, dichloroethylene, chlorobenzene, and chloroform, alcohol solvents such as methanol, ethanol, isopropyl alcohol, butanol, pentanol, hexanol, propanediol, phenol, acetone, methyl isobutyl ketone, and methyl ethyl ketone , ketone solvents such as pentanone, hexanone, cyclohexanone, isophorone and acetophenone, cellosolves such as methyl cellosolve and ethyl cellosolve, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, formic acid Ester solvents such as butyl, ethylene glycol mono-n-butyl ether, ethylene glycol monoiso-butyl ether, ethylene glycol mono-tert-butyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol monoiso-butyl ether, tri Glycol ether solvents, such as ethylene glycol mono-n-butyl ether and tetraethylene glycol mono-n-butyl ether, can be used, These 1 type, or 2 or more types can be used together.

The content of the organic solvent may be 100 to 1000 parts by weight based on 100 parts by weight of the total amount of the acid-modified polyolefin resin, the carboxyl group-containing styrene resin, and the polyphenylene ether resin.

The first adhesive layer 110 and the second adhesive layer 120 may each independently have a thickness of 3 to 30 μm, preferably 6 to 15 μm. If the thickness of the first adhesive layer 110 and the second adhesive layer 120 is less than 3 μm, the adhesion between the insulating layer and the metal layer may be insufficient after manufacturing the flexible circuit board, and when it exceeds 30 μm, the heat resistance of the flexible circuit board decreases. can be

In one embodiment of the present invention, the thickness of the insulating laminate including the insulating layer containing the liquid crystal polymer and the adhesive layer formed on at least one surface of the insulating layer is 10 to 100㎛, preferably 25 to 75㎛ may be have. When the thickness of the insulating laminate is less than 10 μm, a transmission loss rate in a high frequency region may increase, and if it exceeds 100 μm, a radius of curvature may increase, thereby reducing bending resistance.

In one embodiment of the present invention, the first metal layer 20 and the second metal layer 30 are each independently one or more metals or alloys selected from the group consisting of copper, iron, nickel, titanium, aluminum, silver and gold. It may be a thin film of , preferably a copper thin film having excellent electrical conductivity and inexpensive price, that is, a copper foil layer, but is not limited thereto. The copper foil layer may be a layer formed by electrolysis or a layer formed by rolling.

The thickness of the first metal layer 20 and the second metal layer 30 is not particularly limited in the present invention, but may be, for example, each independently 5 to 50 μm, preferably 7 to 15 μm. If the thickness of the metal layers is less than the above range, a heat problem may occur in the flexible metal laminate including the same, and if it exceeds the above range, there may be a problem in that the flexibility of the flexible metal laminate including the same is slightly lowered.

One embodiment of the present invention relates to a method of manufacturing the flexible metal laminate.

A method of manufacturing a flexible metal laminate according to an embodiment of the present invention

heat-treating the insulating layer including the liquid crystal polymer;

forming an adhesive layer on at least one surface of the heat-treated insulating layer to obtain an insulating laminate; and

and bonding a metal layer on the insulating laminate.

The constituent components, layer structure, thickness, heat treatment conditions, etc. of the insulating layer are the same as those described for the flexible metal laminate.

The heat treatment means for the insulating layer is not particularly limited as long as it can be heated at a temperature higher than or equal to the melting point, and for example, a hot roll, a hot air furnace, a ceramic heater, an IR furnace, or a method in which they are used in combination can be used. A hot air heating furnace may be used.

The heat treatment of the insulating layer may be performed on a polyimide film support. Deformation of the insulating layer including the LCP can be prevented by performing heat treatment of the insulating layer on the polyimide film support.

As described in the flexible metal laminate, the heat-treated insulating layer may have an elongation in the MD direction of 13% or more and an elongation in the TD direction of 16% or more.

The components and thickness of the adhesive layer are the same as those described for the flexible metal laminate.

There is no particular limitation on the coating method of the adhesive composition, and for example, various coating methods such as a comma coater, a doctor blade, a wire bar, a die coater, and a gravure coater may be used.

Drying of the adhesive composition may be performed for 30 to 360 seconds, preferably 150 to 240 seconds at a temperature of 100 to 180 ℃, preferably 120 to 150 ℃.

If the drying temperature is less than 100 ℃, the adhesive composition may be undried, and if it exceeds 180 ℃, surface appearance defects such as orange peel may occur.

If the drying time is less than 30 seconds, the adhesive composition may be undried, and if it is more than 360 seconds, overheat treatment may result in poor appearance.

The components and thickness of the metal layer are the same as those described in the flexible metal laminate.

The bonding of the insulating laminate and the metal layer is not particularly limited as long as thermal fusion can be performed, for example, a hot roll, a double belt press, a heating plate, or a method using a combination thereof may be used. In particular, the bonding is performed using a heating plate method can

The bonding may be performed at a temperature of 100 to 200° C., preferably 120 to 150° C., and a pressure (surface pressure) of 1 to 8 MPa, preferably 2 to 5 MPa.

When the bonding temperature is less than 100° C., the adhesion between the insulating laminate and the metal layer may be reduced, and if the bonding temperature is more than 200° C., the melting of the insulating layer may be deepened and an overflow phenomenon may occur.

If the bonding pressure is less than 1 MPa, the adhesion between the insulating laminate and the metal layer may be reduced, and if the bonding pressure is more than 8 MPa, cracks may occur inside the insulating layer due to overpressure, thereby reducing mechanical properties.

The bonding may be performed under the conditions of a temperature increase time of 10 to 60 minutes, a holding time of 30 to 90 minutes, a low temperature of 10 to 60 minutes, and a pressure increase time of 1 minute.

In addition, the bonding may be performed under vacuum conditions within 5 kpa.

After bonding the metal layer, the adhesion between the insulating layer and the metal layer is 0.4 kN/m or more, the dielectric constant at 15 GHz of the insulating laminate is 3.1 or less, and the dielectric loss tangent is 0.0014 or less, and the tensile strength of the flexible metal laminate The strength is 200 MPa or more.

In addition, after the step of bonding the metal layer, when the bending and unfolding operation of the flexible metal laminate in the MD and TD directions at a radius of 1R (R = 1mm) in the 180° condition is repeated, disconnection is repeated during resistance measurement The number of times may be 210 or more.

The adhesion between the insulating layer and the metal layer, the dielectric constant and dielectric loss tangent at 15 GHz of the insulating laminate, and the tensile strength and bending resistance of the flexible metal laminate are the same as those described in the flexible metal laminate.

In the flexible metal laminate according to an embodiment of the present invention, adhesion between the insulating layer and the metal layer may be improved by heat-treating the insulating layer under a specific condition in advance before bonding the insulating layer to the metal layer, and thus drilling for forming a hole in the metal layer Delamination is suppressed during the (drilling) process, so FPCB fabrication is easy, durability can be secured under severe conditions, such as high temperature and/or thermal shock, and has low dielectric constant and dielectric loss tangent even in high frequency bands, so signal loss rate when FPCB is applied In addition to preventing the increase of the FPCB, it also has excellent mechanical properties so that it can be easily molded.

One embodiment of the present invention relates to a printed wiring board using the flexible metal laminate.

The printed wiring board may be manufactured by forming a circuit pattern on at least one metal layer of the laminate through etching or the like.

The printed wiring board may be a flexible printed wiring board.

Hereinafter, the present invention will be described in more detail by way of Examples, Comparative Examples and Experimental Examples. These Examples, Comparative Examples, and Experimental Examples are only for illustrating the present invention, and it is apparent to those skilled in the art that the scope of the present invention is not limited thereto.

Example 1: Preparation of a flexible metal laminate

The LCP film (thickness 25㎛, T _m 293℃, Chiyoda Corporation) was attached to the polyimide (PI) film (50㎛, release treatment PI, SKC Kolon Corporation) as a support and a hot air oven (Model-IPHH-202, Espec) G) and then heat-treated at 295° C. for 60 minutes to prepare a reinforced heat-treated LCP film.

On the heat-treated LCP film, the adhesive composition (acid-modified polyolefin resin-containing low-oil adhesive, Toyobo, acid-modified polypropylene resin (MS-003B) 64.9 parts by weight, SEBS resin (MS-003A) 27.8 parts by weight, ether resin (MS) -040A) 7.3 parts by weight and aromatic epoxy resin (ME-08) containing 1.8 parts by weight) were applied and dried, and an adhesive layer having a thickness of 12.5 μm was prepared on both sides to obtain an insulating laminate.

After laminating a copper foil substrate (thickness 12㎛, manufacturer Mitsui, product name SP-3) on the upper and lower surfaces of the insulating laminate, respectively, put into a vacuum press (Kitagawa seiki, Model-KVHC), and then maintain a temperature of 155 ℃ A flexible metal laminate was obtained by pressurizing for 60 minutes, a pressure of 3.5 Mpa, and a vacuum degree of 0.1 Kpa.

Examples 2 to 8 and Comparative Examples 1 to 15: Preparation of flexible metal laminates

A flexible metal laminate was prepared in the same manner as in Example 1, except that the heat treatment conditions of the LCP film were controlled as shown in Table 1 below.

Experimental example:

The physical properties of the flexible metal laminates prepared in Examples and Comparative Examples were measured by the method described below, and the results are shown in Table 1 below.

(1) Adhesion

A specimen for evaluation was prepared by cutting the flexible metal laminate into a size of 100 mm × 10 mm. The adhesion between the insulating layer and the copper foil was measured using a UTM (Shimadzu) measuring machine under the conditions of a peeling angle of 90˚, a specimen width of 10mm, and a peeling rate of 50mm/min, and the average value was obtained by measuring three specimens.

(2) dielectric properties

After etching the copper foil of the flexible metal laminates of Examples and Comparative Examples, a dielectric constant measuring device (Anritsu Corporation, product name MS46522B) was used at a temperature of 25° C. and a humidity of 50% for the insulating laminate consisting of an insulating layer and an adhesive layer. Thus, the dielectric constant (Dk) and dielectric loss tangent (Df) values at 15 GHz were measured.

(3) elongation

With respect to the heat-treated LCP film, using an Auto Graph (Shimadzu) measuring machine under the conditions of a width of 15 mm, a gage distance of 50 mm before stretching, and a speed of 50 mm/min. was performed to measure the elongation.

(4) Tensile strength

The flexible metal laminates of Examples and Comparative Examples were cut to a size of 100 mm × 25 mm to prepare a specimen for evaluation. The specimen was measured by performing a tensile test using a UTM (Shimadzu Corporation) measuring device under the conditions of a specimen width of 25 mm, a speed of 10 mm/min, and a gage distance of 50 mm until the flexible metal laminate was fractured, and three specimens were measured. Average values are reported.

(5) Flexural resistance

Specimens for evaluation were prepared by cutting the flexible metal laminates of Examples and Comparative Examples into a size of 100 mm×20 mm. Using a folding machine (CFT-120, Covotech), the bending and unfolding operation was repeated in the MD and TD directions, respectively, with a radius of 1R (R = 1mm) at 180°. The number of points where disconnection was confirmed through resistance measurement was measured, and the average value of three specimens was recorded.

division Temperature (℃) time (min) Adhesion (kN/m) dielectric properties Elongation (%) The tensile strength
(Mpa) flexibility
(number) Dk Df MD TD MD TD Comparative Example 1 280 60 0.2 3.1 0.0017 10.2 10.9 289 201 198 Comparative Example 2 120 0.2 3.1 0.0017 12.1 11.2 301 225 183 Comparative Example 3 360 0.2 3.1 0.0018 18 12.1 292 199 202 Comparative Example 4 290 60 0.4 3.1 0.0016 18.3 19.2 295 249 252 Comparative Example 5 120 0.4 3.1 0.0015 22.1 23.1 289 265 261 Comparative Example 6 180 0.5 3.1 0.0015 23.8 22.6 282 259 241 Comparative Example 7 360 0.5 3.1 0.0015 22.1 22.8 281 255 242 Comparative Example 8 295 50 0.7 3.1 0.0015 22.1 21.4 294 248 251 Example 1 60 1.1 3.1 0.0014 22.8 23.4 285 255 276 Example 2 120 1.1 3.1 0.0013 28.2 27.5 282 292 272 Example 3 180 1.3 3.1 0.0012 27.2 27.8 276 268 292 Example 4 360 1.3 3.0 0.0013 26.8 26.7 268 276 268 Comparative Example 9 400 1.2 3.1 0.0015 24.2 24.8 255 261 254 Comparative Example 10 300 50 1.1 3.1 0.0015 24.2 24.8 256 238 202 Example 5 60 1.1 3.1 0.0013 24.8 25.6 242 242 218 Example 6 120 1.1 3.1 0.0014 24.2 22.8 255 228 226 Example 7 180 1.3 3.1 0.0014 24.0 23.6 233 232 231 Example 8 360 1.5 3.0 0.0013 22.8 21.9 228 232 225 Comparative Example 11 400 1.5 3.1 0.0014 19.2 18.7 191 196 201 Comparative Example 12 310 60 1.1 3.1 0.0012 18.2 16.8 188 195 208 Comparative Example 13 120 1.3 3.1 0.0013 18.3 17.2 192 183 192 Comparative Example 14 180 1.4 3.1 0.0012 15.5 16.2 155 189 188 Comparative Example 15 360 1.5 3.0 0.0012 14.2 15.5 132 181 195

Referring to Table 1, the flexible metal laminates of Examples 1 to 8, which were previously heat-treated under specific conditions before bonding the insulating layer containing the liquid crystal polymer to the metal layer, had excellent adhesion between the insulating layer and the metal layer, so that peeling phenomenon during the drilling process This can be suppressed, and it has been shown that the FPCB molding process can be performed more smoothly due to its excellent tensile strength and bending resistance. In addition, it can be seen that the flexible metal laminates of Examples 1 to 8 have lower dielectric constant and dielectric loss tangent even in a high frequency band, so that the signal loss rate can be reduced.

On the other hand, in the flexible metal laminates of Comparative Examples 1 to 15, adhesion, dielectric properties, tensile strength, and bending resistance between the insulating layer and the metal layer cannot be secured at the same time. Otherwise, the molding process of FPCB was found to be difficult.

As the specific part of the present invention has been described in detail above, for those of ordinary skill in the art to which the present invention pertains, it is clear that these specific techniques are only preferred embodiments, and the scope of the present invention is not limited thereto. do. Those of ordinary skill in the art to which the present invention pertains will be able to make various applications and modifications within the scope of the present invention based on the above contents.

Accordingly, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

100: insulating layer 110: first adhesive layer
120: second adhesive layer 10: insulating laminate
20: first metal layer 30: second metal layer

Claims (13)

An insulating laminate comprising an insulating layer comprising a liquid crystal polymer, an adhesive layer formed on at least one surface of the insulating layer, and a metal layer formed on the insulating laminate, the flexible metal laminate comprising:
The adhesion between the insulating layer and the metal layer is 0.4 kN / m or more,
The dielectric constant at 15 GHz of the insulating laminate is 3.1 or less and the dielectric loss tangent is 0.0014 or less,
A flexible metal laminate having a tensile strength of 200 MPa or more of the flexible metal laminate. The flexible metal laminate according to claim 1, wherein the insulating layer has an elongation in the MD direction of 13% or more, and an elongation in the TD direction of 16% or more. The ductility of claim 1 , wherein when the flexible metal laminate is bent and unfolded at a radius of 1R (R = 1mm) in the MD and TD directions at 180°, the number of repetitions of disconnection during resistance measurement is 210 or more. metal laminate. The flexible metal laminate according to claim 1, wherein the flexible metal laminate is manufactured by heat-treating the insulating layer containing the liquid crystal polymer, forming an adhesive layer, and bonding the metal layers. The flexible metal laminate according to claim 4, wherein the heat treatment of the insulating layer is performed at a temperature of T _m to T _m +10°C (T _m is the melting point of the liquid crystal polymer) for 60 to 360 minutes. The flexible metal laminate according to claim 1, wherein the adhesive layer is formed from an adhesive composition comprising an acid-modified polyolefin resin. heat-treating the insulating layer including the liquid crystal polymer;
forming an adhesive layer on at least one surface of the heat-treated insulating layer to obtain an insulating laminate; and
and bonding a metal layer on the insulating laminate. 8. The method of claim 7, wherein, after the bonding of the metal layer, the adhesion between the insulating layer and the metal layer is 0.4 kN/m or more, the dielectric constant at 15 GHz of the insulating laminate is 3.1 or less, and the dielectric loss tangent is 0.0014 or less, and the A method for manufacturing a flexible metal laminate having a tensile strength of 200 MPa or more. The resistance measurement according to claim 7, wherein after the step of bonding the metal layers, bending and unfolding the flexible metal laminate in the MD and TD directions at a radius of 1R (R = 1mm) at a 180° condition is repeated. A manufacturing method in which the number of repetitions during disconnection is 210 or more. The method according to claim 7, wherein the heat treatment of the insulating layer is performed at a temperature of T _m to T _m +10°C (T _m is the melting point of the liquid crystal polymer) for 60 to 360 minutes. The method according to claim 7, wherein the heat treatment of the insulating layer is performed on a polyimide film support. The method according to claim 7, wherein the heat-treated insulating layer has an elongation in the MD direction of 13% or more, and an elongation in the TD direction of 16% or more. A printed wiring board using the flexible metal laminate according to any one of claims 1 to 6.

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