WO2023163101A1 - Laminate, wiring substate, and method for fabricating wiring substrate - Google Patents

Abstract

The present invention addresses the problem of providing a laminate that has a low dielectric loss tangent and, when being laminated on a substrate having wiring, achieves excellent suppression of wiring misalignment. The present invention also addresses the problem of providing a wiring substrate including said laminate and a method for fabricating the wiring substrate.　The laminate according to the present invention comprises a layer A containing a liquid crystal polymer and a layer B disposed on at least one of the surfaces of the layer A. The layer A has an area of 0.2 J/g or greater at a melting peak measured using differential scanning calorimetry. The layer B has an elastic modulus of 500 MPa or less at a temperature of 160°C.

Description

LAMINATED BOARD, WIRING BOARD, AND METHOD FOR MANUFACTURING WIRING BOARD

The present invention relates to a laminate, a wiring board, and a method for manufacturing a wiring board.

The 5th generation (5G) mobile communication system, which is considered to be the next generation communication technology, uses a higher frequency band than before. Therefore, film substrates for circuit boards for 5G mobile communication systems are required to have a lower dielectric loss tangent from the viewpoint of reducing transmission loss in high frequency bands. Material development is underway.

For example, Patent Document 1 describes a thermoplastic liquid crystal polymer film having a toughness within a predetermined range after thermocompression bonding with a conductor layer, and a circuit board formed by laminating a thermoplastic liquid crystal polymer film and a conductor layer. ing.

WO2016/174868

From the viewpoint of further reducing the transmission loss in the high frequency band when using a wiring board having a liquid crystal polymer film and wiring in a high frequency circuit board, further reduction of the dielectric loss tangent in the member between the wiring is required. It is
The inventors of the present invention have studied a technique for reducing the dielectric loss tangent in a wiring board having a base material such as a liquid crystal polymer film and wiring while referring to the technique described in Patent Document 1. As a result, depending on the liquid crystal polymer film used, While it is possible to reduce the dielectric loss tangent, when laminating such a liquid crystal polymer film to wiring, a phenomenon occurs in which the position of the wiring is displaced from the desired position (hereinafter also referred to as "wiring displacement"). It was found that there is a tendency, and that there is room for further technical improvement.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a laminate having a low dielectric loss tangent and excellent performance in suppressing displacement of wiring when laminated with a base material with wiring. and
Another object of the present invention is to provide a wiring board having the laminate and a method for manufacturing the wiring board.

As a result of earnestly examining the above problem, the inventors found that the above problem can be solved by the following configuration.

[1] It has a layer A containing a liquid crystal polymer and a layer B arranged on at least one surface of the layer A, and the area of the melting peak of the layer A measured by differential scanning calorimetry is 0.5. 2 J/g or more, and the layer B has an elastic modulus at 160° C. of 500 MPa or less.
[2] The laminate according to [1], wherein the liquid crystal polymer contains two or more repeating units derived from a dicarboxylic acid.
[3] The liquid crystal polymer contains repeating units derived from 6-hydroxy-2-naphthoic acid, repeating units derived from an aromatic diol, repeating units derived from terephthalic acid, and derived from 2,6-naphthalenedicarboxylic acid. The laminate according to [1] or [2], which has at least one selected from the group consisting of repeating units.
[4] The laminate according to any one of [1] to [3], wherein the layer B has a thickness of 5 to 30 μm.
[5] The laminate according to any one of [1] to [4], wherein the layer B contains a thermoplastic resin.
[6] The layer B is a layer formed using a composition containing a thermoplastic resin and a reactive compound, and the content of the reactive compound is 5 to 20 with respect to the total mass of the composition. The laminate according to [5], which is % by mass.
[7] The laminate according to any one of [1] to [6], further comprising an intermediate layer between the layer A and the layer B.
[8] A wiring board comprising the laminate according to any one of [1] to [7], and a wiring-attached base material having a base material and wiring.
[9] The wiring board according to [8], wherein the wiring has a thickness of 5 to 40 μm.
[10] The laminate according to any one of [1] to [7] and a substrate with wiring having a substrate and wiring are laminated so that the layer B of the laminate and the wiring are opposed to each other, and are laminated. A method for manufacturing a wiring substrate, wherein the wiring substrate is manufactured by thermocompression bonding the laminate and the base material with wiring.

According to the present invention, it is possible to provide a laminate having a low dielectric loss tangent and excellent performance in suppressing positional displacement of wiring when laminated with a base material with wiring. Further, according to the present invention, it is possible to provide a wiring board having a laminate and a method for manufacturing the wiring board.

The present invention will be described in detail below.
The description of the constituent elements described below may be made based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.
As used herein, the term "organic group" refers to a group containing at least one carbon atom.

In this specification, when a film-like member such as a laminate is long, the width direction means the width direction and the TD (transverse direction) direction of the film-like member, and the length direction means the film. means the longitudinal direction and the MD (machine direction) direction of the shaped member.
In this specification, for each component, one type of substance corresponding to each component may be used alone, or two or more types may be used. Here, when two or more substances are used for each component, the content of that component refers to the total content of the two or more substances unless otherwise specified.
In the present specification, the term "~" is used to include the numerical values before and after it as lower and upper limits.
In this specification, the dielectric loss tangent measured under conditions of a temperature of 23° C. and a frequency of 28 GHz is also referred to as “standard dielectric loss tangent”.

[Laminate]
The laminate of the present invention has a layer A containing a liquid crystal polymer and a layer B disposed on at least one surface of layer A, and measured by differential scanning calorimetry (DSC) of layer A. The melting peak area (hereinafter also referred to as “melting peak area”) is 0.2 J/g or more, and the elastic modulus of layer B at 160° C. is 500 MPa or less.

The detailed mechanism by which the problems of the present invention are solved by a laminate having a layer A containing a liquid crystal polymer and having a predetermined melting peak area and a layer B having a predetermined elastic modulus under high temperature conditions is clarified. Although not true, the present inventors presume as follows.
That is, the liquid crystal polymer film, which has a melting peak area within a predetermined range and can contribute to reducing the transmission loss of the wiring substrate, tends to have high crystallinity. Wiring displacement may occur along the in-plane direction due to the pressure during thermocompression bonding and the shape of the wiring. On the other hand, by providing the layer B having an elastic modulus of 500 MPa or less at a high temperature of 160° C. on the surface, the layer B is appropriately deformed when attached to the wiring, thereby suppressing the displacement of the wiring and suppressing the displacement of the wiring in the in-plane direction. is presumed to suppress the wiring misalignment. In addition, since the layer A having a melting peak area equal to or larger than a predetermined value exists as a core layer, the dielectric loss tangent of the entire laminate is suppressed to be low. As a result, it is believed that a laminated base material can be obtained that is excellent in performance of suppressing wiring deviation when laminated on wiring, and in which the dielectric loss tangent of the entire laminated body is suppressed to be low.

In the present specification, when the dielectric loss tangent of the laminate is excellent and/or the performance of suppressing misalignment of wiring when laminated with a substrate with wiring (hereinafter also referred to as “wiring misalignment suppression performance”) is excellent. , "The effect of the present invention is excellent" is also described.
The laminate of the present invention will be described in detail below.

[Layer A]
The laminate of the present invention has a layer A containing a liquid crystal polymer and having a melting peak area of 0.2 J/g or more.
Hereinafter, the layer A will be described in order of the constituent components and physical properties of the layer A.

<Constituent>
(liquid crystal polymer)
The liquid crystal polymer contained in Layer A is not particularly limited, and examples thereof include melt-moldable liquid crystal polymers.
As the liquid crystal polymer, a thermotropic liquid crystal polymer is preferred. A thermotropic liquid crystal polymer means a polymer that exhibits liquid crystallinity in a molten state when heated within a predetermined temperature range.
The thermotropic liquid crystal polymer is not particularly limited in terms of its chemical composition as long as it is a liquid crystal polymer that can be melt-molded. mentioned.
As the liquid crystal polymer, for example, thermoplastic liquid crystal polymers described in WO 2015/064437 and JP 2019-116586 can be used.

More specific liquid crystal polymers are selected from the group consisting of aromatic hydroxycarboxylic acids, aromatic or aliphatic diols, aromatic or aliphatic dicarboxylic acids, aromatic diamines, aromatic hydroxylamines, and aromatic aminocarboxylic acids. A thermoplastic liquid crystalline polyester or a thermoplastic liquid crystalline polyester amide having a repeating unit derived from at least one selected is exemplified.

Aromatic hydroxycarboxylic acids include parahydroxybenzoic acid, metahydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, and 4-(4-hydroxyphenyl)benzoic acid. These compounds may have substituents such as halogen atoms, lower alkyl groups and phenyl groups. Among them, parahydroxybenzoic acid or 6-hydroxy-2-naphthoic acid is preferred.
Aromatic diols are preferred as aromatic or aliphatic diols. Aromatic diols include hydroquinone, 4,4′-dihydroxybiphenyl, 3,3′-dimethyl-1,1′-biphenyl-4,4′-diol and acylates thereof, and hydroquinone or 4,4 '-Dihydroxybiphenyl is preferred.
Aromatic dicarboxylic acids are preferred as aromatic or aliphatic dicarboxylic acids. Aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, with terephthalic acid being preferred.
Aromatic diamines, aromatic hydroxylamines, and aromatic aminocarboxylic acids include, for example, p-phenylenediamine, 4-aminophenol, and 4-aminobenzoic acid.

Among the above repeating units, the liquid crystal polymer preferably contains a repeating unit derived from a dicarboxylic acid (aromatic or aliphatic dicarboxylic acid). It is more preferable to include two or more of As the dicarboxylic acid in this case, the aromatic dicarboxylic acid described above is preferable, and terephthalic acid, isophthalic acid, or 2,6-naphthalenedicarboxylic acid is more preferable.

Moreover, the liquid crystal polymer preferably has at least one selected from the group consisting of repeating units represented by the following formulas (1) to (3).
-O-Ar1-CO- (1)
-CO-Ar2-CO- (2)
-X-Ar3-Y- (3)
In formula (1), Ar1 represents a phenylene group, naphthylene group or biphenylylene group.
In formula (2), Ar2 represents a phenylene group, a naphthylene group, a biphenylylene group, or a group represented by formula (4) below.
In formula (3), Ar3 represents a phenylene group, a naphthylene group, a biphenylylene group, or a group represented by the following formula (4), and X and Y each independently represent an oxygen atom or an imino group.
-Ar4-Z-Ar5- (4)
In formula (4), Ar4 and Ar5 each independently represent a phenylene group or a naphthylene group, and Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group or an alkylene group.
The phenylene group, the naphthylene group and the biphenylene group may have substituents selected from the group consisting of halogen atoms, alkyl groups and aryl groups.

Among them, the liquid crystal polymer is a repeating unit derived from an aromatic hydroxycarboxylic acid represented by the above formula (1), and an aromatic diol represented by the above formula (3) in which both X and Y are oxygen atoms. It preferably has at least one selected from the group consisting of a repeating unit derived from the compound and a repeating unit derived from the aromatic dicarboxylic acid represented by the above formula (2).
Further, the liquid crystal polymer more preferably has at least a repeating unit derived from an aromatic hydroxycarboxylic acid, and a repeating unit derived from parahydroxybenzoic acid and a repeating unit derived from 6-hydroxy-2-naphthoic acid. It is more preferable to have at least one selected from the group consisting of, and it is particularly preferable to have a repeating unit derived from parahydroxybenzoic acid and a repeating unit derived from 6-hydroxy-2-naphthoic acid.

In another preferred embodiment, the effects of the present invention are more excellent, and the liquid crystal polymer includes repeating units derived from 6-hydroxy-2-naphthoic acid, repeating units derived from an aromatic diol, and repeating units derived from terephthalic acid. It is more preferable to have at least one selected from the group consisting of repeating units and repeating units derived from 2,6-naphthalenedicarboxylic acid, repeating units derived from 6-hydroxy-2-naphthoic acid, aromatic diols It is more preferable to have all repeating units derived from , repeating units derived from terephthalic acid, and repeating units derived from 2,6-naphthalenedicarboxylic acid.

When the liquid crystal polymer contains repeating units derived from an aromatic hydroxycarboxylic acid, the composition ratio thereof is preferably 50 to 65 mol % with respect to all repeating units of the liquid crystal polymer. It is also preferred that the liquid crystal polymer has only repeating units derived from aromatic hydroxycarboxylic acid.
When the liquid crystal polymer contains repeating units derived from an aromatic diol, the composition ratio thereof is preferably 17.5 to 25 mol % with respect to all repeating units of the liquid crystal polymer.
When the liquid crystal polymer contains repeating units derived from an aromatic dicarboxylic acid, the composition ratio thereof is preferably 11 to 23 mol % with respect to all repeating units of the liquid crystal polymer.
When the liquid crystal polymer contains repeating units derived from any one of an aromatic diamine, an aromatic hydroxylamine and an aromatic aminocarboxylic acid, the composition ratio thereof is preferably 2 to 8 mol% with respect to all repeating units of the liquid crystal polymer. .

The method for synthesizing the liquid crystal polymer is not particularly limited, and the compound can be synthesized by polymerizing the above compounds by known methods such as melt polymerization, solid phase polymerization, solution polymerization and slurry polymerization.
A commercially available product may be used as the liquid crystal polymer. Examples of commercial products of liquid crystal polymers include "Laperos" manufactured by Polyplastics Co., Ltd., "Vectra" manufactured by Celanese, "UENO LCP" manufactured by Ueno Pharmaceutical Co., Ltd., "Sumika Super LCP" manufactured by Sumitomo Chemical Co., Ltd., and ENEOS Co., Ltd. "Zeidar" manufactured by the company and "Siveras" manufactured by Toray Industries, Inc. can be mentioned.
In the layer A, the liquid crystal polymer may form a chemical bond with an optional component such as a cross-linking agent or a compatible component (reactive compatibilizer). This point also applies to components other than the liquid crystal polymer.

The standard dielectric loss tangent of the liquid crystal polymer is preferably less than 0.002, more preferably 0.0015 or less, and even more preferably 0.001 or less, in that a laminate with a reduced standard dielectric loss tangent can be easily produced. The lower limit is not particularly limited, and may be, for example, 0.0001 or more.
When the layer A contains two or more liquid crystal polymers, the "dielectric loss tangent of the liquid crystal polymer" means the mass average value of the dielectric loss tangents of the two or more liquid crystal polymers.

The standard dielectric loss tangent of the liquid crystal polymer contained in layer A can be measured by the following method.
First, after being immersed in an organic solvent (e.g., pentafluorophenol) that is 1000 times the total weight of the layer A, it is heated at 120° C. for 12 hours to remove the organic solvent-soluble components including the liquid crystal polymer from the organic solvent. dissolve in. Next, the eluate containing the liquid crystal polymer and the non-eluted components are separated by filtration. Subsequently, acetone is added as a poor solvent to the eluate to precipitate a liquid crystal polymer, and the precipitate is separated by filtration.
A PTFE (polytetrafluoroethylene) tube (outer diameter: 2.5 mm, inner diameter: 1.5 mm, length: 10 mm) is filled with the resulting precipitates, and a cavity resonator (for example, Kanto Denshi Applied Development Co., Ltd. “CP -531”), the dielectric properties were measured by the cavity resonator perturbation method under the conditions of a temperature of 23 ° C. and a frequency of 28 GHz, and the effect of the voids in the PTFE tube was corrected by the Bruggeman equation and the void ratio. , yielding the standard dielectric loss tangent of the liquid crystal polymer.
The porosity (volume ratio of voids in the tube) is calculated as follows. The volume of the space inside the tube is determined from the inner diameter and length of the tube. Next, after measuring the weight of the tube before and after filling with the precipitate to obtain the mass of the filled precipitate, the volume of the filled precipitate is obtained from the obtained mass and the specific gravity of the precipitate. The porosity can be calculated by dividing the volume of the precipitate thus obtained by the volume of the space in the tube obtained above to calculate the filling rate.
When a commercially available liquid crystal polymer is used, the value of the dielectric loss tangent listed as the catalog value of the commercially available product may be used.

The liquid crystal polymer preferably has a melting point Tm of 250° C. or higher, more preferably 280° C. or higher, and even more preferably 310° C. or higher, in terms of better heat resistance.
Although the upper limit of the melting point Tm of the liquid crystal polymer is not particularly limited, it is preferably 400° C. or lower, more preferably 380° C. or lower, in terms of better moldability.
The melting point Tm of the liquid crystal polymer can be obtained by measuring the temperature at which the endothermic peak appears using a differential scanning calorimeter (“DSC-60A” manufactured by Shimadzu Corporation). When using a commercial product of liquid crystal polymer, the melting point Tm described as the catalog value of the commercial product may be used.

Although the number average molecular weight (Mn) of the liquid crystal polymer is not particularly limited, it is preferably 10,000 to 600,000, more preferably 30,000 to 150,000.
In the present specification, the number average molecular weights of polymers and resins including liquid crystal polymers are converted values of standard polystyrene measured by Gel Permeation Chromatography (GPC). GPC measurement can be performed using the following apparatus and conditions.
"HLC (registered trademark)-8320GPC" manufactured by Tosoh Corporation is used as a measurement apparatus, and two columns of TSKgel (registered trademark) SuperHM-H (6.0 mm ID x 15 cm, manufactured by Tosoh Corporation) are used. A solvent (eluent) for dissolving the liquid crystal polymer is not particularly limited, but an example thereof is a mixed solution of pentafluorophenol/chloroform=1/2 (mass ratio). The measurement conditions are a sample concentration of 0.03% by mass, a flow rate of 0.6 ml/min, a sample injection volume of 20 μL, and a measurement temperature of 40°C. Detection is performed using an RI (differential refraction) detector.
The calibration curve is "Standard sample TSK standard, polystyrene" manufactured by Tosoh Corporation: "F-40", "F-20", "F-4", "F-1", "A-5000", "A -2500", "A-1000" and 8 samples of "n-propylbenzene".

A liquid crystal polymer may be used individually by 1 type, and may be used in combination of 2 or more type.
The content of the liquid crystal polymer is preferably 50% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, based on the total mass of the layer A, from the viewpoint that the effects of the present invention are more excellent. The upper limit is not particularly limited, and may be 100% by mass.
The contents of the liquid crystal polymer and components described later in Layer A can be measured by known methods such as infrared spectroscopy and gas chromatography-mass spectrometry.

(Optional component)
Layer A may contain optional components other than the liquid crystal polymer. Optional components include compatible components, heat stabilizers, and additives described later.

- compatible components -
The compatible component includes, for example, a polymer (non-reactive compatibilizer) having a portion that is highly compatible or highly compatible with the liquid crystal polymer, and reactivity with the terminal phenolic hydroxyl group or carboxy group of the liquid crystal polymer. Examples include polymers having groups (reactive compatibilizers).
The reactive group possessed by the reactive compatibilizer is preferably an epoxy group or a maleic anhydride group.
As the compatible component, a copolymer having a portion with high compatibility or affinity with polyolefin is preferred. Further, when the film contains polyolefin and a compatibilizing component, the compatibilizing component is preferably a reactive compatibilizer because it can finely disperse the polyolefin.
The compatibilizing component (especially the reactive compatibilizing agent) may form a chemical bond with a component such as a liquid crystal polymer in the layer A.

Examples of reactive compatibilizers include epoxy group-containing polyolefin copolymers, epoxy group-containing vinyl copolymers, maleic anhydride-containing polyolefin copolymers, maleic anhydride-containing vinyl copolymers, oxazoline group-containing Examples include polyolefin copolymers, oxazoline group-containing vinyl copolymers, and carboxy group-containing olefin copolymers. Among them, an epoxy group-containing polyolefin copolymer or a maleic anhydride-grafted polyolefin copolymer is preferable.

Examples of epoxy group-containing polyolefin copolymers include ethylene/glycidyl methacrylate copolymer, ethylene/glycidyl methacrylate/vinyl acetate copolymer, ethylene/glycidyl methacrylate/methyl acrylate copolymer, and ethylene/glycidyl methacrylate copolymer. Polystyrene graft copolymer to coalesce (EGMA-g-PS), polymethyl methacrylate graft copolymer to ethylene/glycidyl methacrylate copolymer (EGMA-g-PMMA), and ethylene/glycidyl methacrylate copolymer to of acrylonitrile/styrene graft copolymer (EGMA-g-AS).
Examples of commercially available epoxy group-containing polyolefin copolymers include Bond First 2C and Bond First E manufactured by Sumitomo Chemical Co., Ltd.; Lotadar manufactured by Arkema; and Modiper A4100 and Modiper A4400 manufactured by NOF Corporation. is mentioned.

Examples of epoxy group-containing vinyl copolymers include glycidyl methacrylate-grafted polystyrene (PS-g-GMA), glycidyl methacrylate-grafted polymethyl methacrylate (PMMA-g-GMA), and glycidyl methacrylate-grafted polyacrylonitrile (PAN-g -GMA).

Examples of maleic anhydride-containing polyolefin copolymers include maleic anhydride-grafted polypropylene (PP-g-MAH), maleic anhydride-grafted ethylene/propylene rubber (EPR-g-MAH), and maleic anhydride-grafted ethylene. /propylene/diene rubber (EPDM-g-MAH).
Commercially available maleic anhydride-containing polyolefin copolymers include, for example, Orevac G series manufactured by Arkema; and FUSABOND E series manufactured by Dow Chemical.

Examples of maleic anhydride-containing vinyl copolymers include maleic anhydride-grafted polystyrene (PS-g-MAH), maleic anhydride-grafted styrene/butadiene/styrene copolymer (SBS-g-MAH), maleic anhydride-grafted Styrene/ethylene/butene/styrene copolymers (SEBS-g-MAH), and styrene/maleic anhydride copolymers and acrylic acid ester/maleic anhydride copolymers.
Commercially available maleic anhydride-containing vinyl copolymers include Tuftec M series (SEBS-g-MAH) manufactured by Asahi Kasei Corporation.

Other compatible components include oxazoline-based compatibilizers (eg, bisoxazoline-styrene-maleic anhydride copolymer, bisoxazoline-maleic anhydride-modified polyethylene, and bisoxazoline-maleic anhydride-modified polypropylene). , elastomeric compatibilizer (e.g., aromatic resin, petroleum resin), ethylene glycidyl methacrylate copolymer, ethylene maleic anhydride ethyl acrylate copolymer, ethylene glycidyl methacrylate-acrylonitrile styrene, acid-modified polyethylene wax, COOH conversion polyethylene graft polymer, COOH polypropylene graft polymer, polyethylene-polyamide graft copolymer, polypropylene-polyamide graft copolymer, methyl methacrylate-butadiene-styrene copolymer, acrylonitrile-butadiene rubber, EVA-PVC-graft copolymer, Vinyl acetate-ethylene copolymer, ethylene-α-olefin copolymer, propylene-α-olefin copolymer, hydrogenated styrene-isopropylene-block copolymer, and amine-modified styrene-ethylene-butene-styrene copolymer polymers.

Also, an ionomer resin may be used as a compatible component.
Such ionomer resins include, for example, ethylene-methacrylic acid copolymer ionomer, ethylene-acrylic acid copolymer ionomer, propylene-methacrylic acid copolymer ionomer, propylene-acrylic acid copolymer ionomer, butylene-acrylic acid Copolymer ionomer, ethylene-vinyl sulfonic acid copolymer ionomer, styrene-methacrylic acid copolymer ionomer, sulfonated polystyrene ionomer, fluorine ionomer, telechelic polybutadiene acrylic acid ionomer, sulfonated ethylene-propylene-diene copolymer Ionomers, hydrogenated polypentamer ionomers, polypentamer ionomers, poly(vinylpyridium salt) ionomers, poly(vinyltrimethylammonium salt) ionomers, poly(vinylbenzylphosphonium salt) ionomers, styrene-butadiene acrylic acid copolymer ionomers , polyurethane ionomers, sulfonated styrene-2-acrylamido-2-methylpropane sulfate ionomers, acid-amine ionomers, aliphatic ionenes, and aromatic ionenes.

When layer A contains a compatible component, the content thereof is preferably 0.05 to 30% by mass, more preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, based on the total mass of layer A. % by mass is more preferred.

-Heat stabilizer-
Layer A may contain a heat stabilizer for the purpose of suppressing thermal oxidation deterioration during melt extrusion film formation and improving the flatness and smoothness of the layer A surface.
Thermal stabilizers include, for example, phenol-based stabilizers and amine-based stabilizers that have a radical-scavenging action; phosphite-based stabilizers and sulfur-based stabilizers that have a peroxide-decomposing action; hybrid type stabilizers having a decomposing action of substances.

Phenolic stabilizers include, for example, hindered phenol stabilizers, semi-hindered fail stabilizers, and less hindered phenol stabilizers.
Examples of commercially available hindered phenol stabilizers include Adekastab AO-20, AO-50, AO-60, and AO-330 manufactured by ADEKA Corporation; and Irganox 259, 1035, and 1098 manufactured by BASF. mentioned.
Commercially available semi-hindered phenolic stabilizers include, for example, Adekastab AO-80 manufactured by ADEKA Corporation; and Irganox245 manufactured by BASF.
Examples of commercial products of resin hindered phenol-based stabilizers include Nocrac 300 manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., and Adekastab AO-30 and AO-40 manufactured by ADEKA Corporation.
Commercially available phosphite-based stabilizers include, for example, Adekastab 2112, PEP-8, PEP-36, and HP-10 manufactured by ADEKA Corporation.
Commercially available hybrid stabilizers include Sumilizer GP manufactured by Sumitomo Chemical Co., Ltd., for example.

As the heat stabilizer, a hindered phenol stabilizer, a semi-hindered phenol stabilizer, or a phosphite stabilizer is preferable, and a hindered phenol stabilizer is more preferable, because the heat stabilizing effect is more excellent. . On the other hand, in terms of electrical properties, semi-hindered phenol-based stabilizers or phosphite-based stabilizers are more preferable.

A heat stabilizer may be used individually by 1 type, and may use 2 or more types.
When the layer A contains a heat stabilizer, the content of the heat stabilizer is preferably 0.0001 to 10% by mass, more preferably 0.01 to 5% by mass, more preferably 0.1% by mass, based on the total mass of the layer A. ~2% by mass is more preferred.

-Additive-
Layer A may contain additives other than the above components. Additives include plasticizers, lubricants, inorganic and organic particles, and UV absorbers.

Plasticizers include alkylphthalylalkylglycolate compounds, bisphenol compounds (bisphenol A, bisphenol F), alkylphthalylalkylglycolate compounds, phosphoric acid ester compounds, carboxylic acid ester compounds, and polyhydric alcohols. The plasticizer content may be 0 to 5% by weight relative to the total weight of layer A.
Lubricants include fatty acid esters and metallic soaps (eg inorganic stearates). The lubricant content may be from 0 to 5% by weight relative to the total weight of layer A.
Layer A may contain inorganic particles and/or organic particles as a reinforcing material, a matting agent, a dielectric constant or a dielectric loss tangent improving material. Inorganic particles include silica, titanium oxide, barium sulfate, talc, zirconia, alumina, silicon nitride, silicon carbide, calcium carbonate, silicate, glass beads, graphite, tungsten carbide, carbon black, clay, mica, carbon fiber, Glass fibers and metal powders are mentioned. Organic particles include crosslinked acrylics and crosslinked styrenes. The content of inorganic particles and organic particles may be from 0 to 50% by weight relative to the total weight of layer A.
UV absorbers include salicylate compounds, benzophenone compounds, benzotriazole compounds, substituted acrylonitrile compounds, and s-triazine compounds. The content of UV absorbers may be from 0 to 5% by weight relative to the total weight of layer A.

Moreover, the layer A may contain a polymer component other than the liquid crystal polymer and the compatible component as long as the effect of the present invention is not impaired.
Examples of the polymer component include thermoplastic resins such as polyolefin, polyethylene terephthalate, modified polyethylene terephthalate, polycarbonate, polyarylate, polyamide, polyphenylene sulfide, and polyester ether ketone.

<Physical properties>
(area of melting peak)
The melting peak area of Layer A is 0.2 J/g or more.
The melting peak area of the layer A is preferably 0.5 J/g or more, more preferably 1.5 J/g or more, and still more preferably 2.0 J/g or more, from the viewpoint that the effects of the present invention are more excellent. 2.1 J/g or more is particularly preferred.
Although the upper limit of the melting peak area of layer A is not particularly limited, it is preferably 30 J/g or less.

The melting peak area (unit: J / g) of layer A is a curve (DSC curve) showing the change in the endothermic value of the film using a differential scanning calorimeter (eg, "DSC-60A" manufactured by Shimadzu Corporation). can be obtained by calculating the area of the endothermic peak appearing in . A detailed method for calculating the melting peak area will be described in Examples below.
As a method for producing Layer A containing a liquid crystal polymer and having a melting peak area within the above range, for example, a film containing a liquid crystal polymer is produced according to the method for producing Layer A described later, and the produced film is subjected to predetermined conditions. A method of performing an annealing treatment by heating with is mentioned.

(thickness)
The thickness of layer A is preferably 5 to 1000 μm, more preferably 10 to 500 μm, even more preferably 20 to 200 μm.
The thickness of each layer of the laminate and the thickness of the laminate can be arbitrarily selected from an observation image obtained by observing a cross section along the thickness direction of the laminate using a scanning electron microscope (SEM). It is an arithmetic mean value obtained by measuring the thickness of each layer or laminate at 100 different points and averaging the obtained measured values.

(elastic modulus)
The elastic modulus of layer A at 160° C. is not particularly limited, but is preferably 500 MPa or more. The upper limit is not particularly limited, and is, for example, 2000 MPa or less.
The elastic modulus at 160° C. of Layer A and Layer B below, which constitute the laminate, is the elastic modulus of each layer in a cross section obtained by cutting the laminate along the thickness direction, under a temperature environment of 160° C., as described in ISO 14577. It is an indentation modulus obtained by measuring using a nanoindenter according to the method of. A specific method for measuring the elastic modulus of each layer will be described in Examples below.

[Layer B]
The laminate has Layer B on at least one surface of Layer A.
The laminate may have one layer B on one surface of layer A, or two layers B on both surfaces of layer A. If the laminate has two layers B, the two layers B may be the same or different.

<Elastic modulus>
The elastic modulus of layer B at 160° C. is 500 MPa or less. The elastic modulus of the layer B at 160° C. is preferably 50 MPa or less, more preferably 20 MPa or less, from the viewpoint that the effects of the present invention are more excellent. Although the lower limit is not particularly limited, it is preferably 0.01 MPa or more from the viewpoint of better handleability.
The elastic modulus of layer B at 160° C. can be adjusted by selecting the constituents of layer B, for example.

<Constituent>
(resin)
The components constituting layer B are not particularly limited as long as the elastic modulus of layer B at 160° C. is within the above range.
Layer B contains, for example, a thermoplastic resin as a component. Layer B is preferably formed using a composition containing a thermoplastic resin and a reactive compound to be described later.
Examples of thermoplastic resins contained in layer B include polyolefins, (meth)acrylic resins, polyvinyl cinnamate, polycarbonates, polyimides, polyamideimides, polyesterimides, polyetherimides, polyetherketones, polyetheretherketones, poly Ethersulfone, polysulfone, polyparaxylene, polyester, polyvinyl acetal, polyvinyl chloride, polyvinyl acetate, polyamide, polystyrene, polyurethane, polyvinyl alcohol, cellulose acylate, syndiotactic polystyrene, silicone resin, alkyd resin, maleic acid resin , aromatic sulfonamides, benzoguanamine resins, and silicone elastomers.

Among them, polyolefin is preferable as a constituent component of the layer B in terms of better electrical properties.
As used herein, "polyolefin" intends a polymer (polyolefin resin) having repeating units derived from an olefin.
The olefin from which the repeating units constituting the polyolefin are derived is not particularly limited as long as it is an aliphatic hydrocarbon having an ethylenically unsaturated group in the molecule, and may be linear or branched. The olefin may have a cyclic structure. The number of carbon atoms in the olefin is, for example, an integer of 2-10, preferably an integer of 2-6.

The polyolefin may be a copolymer having repeating units derived from olefins and repeating units derived from monomers other than olefins. Monomers other than olefins include, for example, acrylate, methacrylate, styrene, and vinyl acetate monomers.
Moreover, it is preferable that the polyolefin does not substantially contain the reactive groups of the reactive compounds described later. The content of the repeating unit having a reactive group in the polyolefin is preferably 0 to 3% by mass with respect to the total mass of the polyolefin.

Polyolefins include, for example, polyethylene, polypropylene (PP), polymethylpentene (“TPX” manufactured by Mitsui Chemicals, Inc.), hydrogenated polybutadiene, cycloolefin polymers (COP, “Zeonor” manufactured by Nippon Zeon Co., Ltd.), and , and cycloolefin copolymers of acyclic olefins and cycloolefins (COC, "APEL" manufactured by Mitsui Chemicals, Inc., etc.).
The polyethylene may be either high density polyethylene (HDPE) or low density polyethylene (LDPE), with LDPE being preferred and linear low density polyethylene (LLDPE) being more preferred.
Examples of polyolefins having repeating units derived from monomers other than olefins include styrene-ethylene/butylene-styrene copolymers (SEBS) and hydrogenated SEBS.

Among them, the polyolefin preferably has repeating units derived from ethylene or propylene, and more preferably has repeating units derived from ethylene.
Polyolefin is preferably polyethylene, COP, COC or SEBS, more preferably polyethylene or SEBS, and even more preferably low density polyethylene (LDPE).

The thermoplastic resin may be used alone or in combination of two or more.
The content of the thermoplastic resin (more preferably polyolefin) is preferably 60 to 99.9% by mass, more preferably 70 to 99% by mass, and even more preferably 80 to 95% by mass, relative to the total mass of layer B. .

(reactive compound)
Layer B may comprise a reaction product of a compound having reactive groups. Hereinafter, compounds having a reactive group and their reaction products are also collectively referred to as "reactive compounds".
Layer B preferably comprises a reactive compound.
The reactive group possessed by the reactive compound is preferably a group capable of reacting with a group that may exist on the surface of layer A (in particular, a group having an oxygen atom such as a carboxy group and a hydroxy group).
Examples of reactive groups include epoxy groups, oxetanyl groups, isocyanate groups, acid anhydride groups, carbodiimide groups, N-hydroxyester groups, glyoxal groups, imidoester groups, halogenated alkyl groups, and thiol groups. , an epoxy group, an acid anhydride group, and a carbodiimide group are preferred, and an epoxy group is more preferred.

Specific examples of reactive compounds having an epoxy group include aromatic glycidylamine compounds (e.g., N,N-diglycidyl-4-glycidyloxyaniline, 4,4′-methylenebis(N,N-diglycidylaniline), N , N-diglycidyl-o-toluidine and N,N,N',N'-tetraglycidyl-m-xylylenediamine, 4-t-butylphenylglycidyl ether), aliphatic glycidylamine compounds (e.g., 1,3 -bis(diglycidylaminomethyl)cyclohexane, etc.), as well as aliphatic glycidyl ether compounds (eg, sorbitol polyglycidyl ether). Among them, aromatic glycidylamine compounds are preferable because the effects of the present invention are more excellent.

Specific examples of the reactive compound having an acid anhydride group include tetracarboxylic dianhydrides (eg, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 3,3′,4,4 '-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, oxydiphthalic dianhydride, diphenylsulfone-3,4,3' ,4'-tetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)sulfide dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3 ,3-hexafluoropropane dianhydride, 2,3,3′,4′-benzophenonetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 2,2-bis(3 ,4-dicarboxyphenyl)propane dianhydride, p-phenylene bis (trimellitic monoester anhydride), p-biphenylene bis (trimellitic monoester anhydride), m-terphenyl-3,4 ,3′,4′-tetracarboxylic dianhydride, p-terphenyl-3,4,3′,4′-tetracarboxylic dianhydride, 1,3-bis(3,4-dicarboxyphenoxy) Benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)biphenyl dianhydride, 2,2-bis[( 3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, and 4 ,4′-(2,2-hexafluoroisopropylidene)diphthalic dianhydride).

Specific examples of reactive compounds having a carbodiimide group include monocarbodiimide compounds (e.g., dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, t-butylisopropylcarbodiimide, diphenylcarbodiimide, di-t-butylcarbodiimide, di-β-naphthylcarbodiimide and N,N'-di-2,6-diisopropylphenylcarbodiimide), and polycarbodiimide compounds (e.g., US Pat. No. 2,941,956, JP-B-47-033279, J 28, p.2069-2075 (1963) and Chemical Review 1981, Vol.
Commercially available reactive compounds having a carbodiimide group include Carbodilite (registered trademark) HMV-8CA, LA-1, and V-03 (all manufactured by Nisshinbo Chemical Co., Ltd.), Stabaxol (registered trademark) P, P100, and P400 (both manufactured by Rhein Chemie) and Stabilizer 9000 (trade name, manufactured by Rashih Chemie).

Although the number of reactive groups possessed by the reactive compound is one or more, three or more are preferable from the viewpoint of better adhesion of the metal layer.
The number of reactive groups possessed by the reactive compound is preferably 6 or less, more preferably 5 or less, and even more preferably 4 or less, from the viewpoint that the effects of the present invention are more excellent.

One type of reactive compound may be used alone, or two or more types may be used.
The content of the reactive compound is preferably 0.1 to 40% by mass, more preferably 1 to 30% by mass, more preferably 5 to 20% by mass, with respect to the total mass of the layer B in that the effect of the present invention is more excellent. % is more preferred, and 5 to 15% by mass is particularly preferred.

Layer B may contain components other than the resin and the reactive compound. Other components contained in Layer B include an inorganic filler, a curing catalyst, a flame retardant, and the like.
The content of other components is preferably 0.1 to 40% by mass, more preferably 1 to 30% by mass, and even more preferably 3 to 20% by mass, based on the total mass of Layer B.
The layer B may contain an organic solvent and water, but the content of the organic solvent and water relative to the total weight of the layer B is preferably 500 ppm by mass or less, respectively, in order to further suppress the generation of bubbles. , 100 ppm by mass or less. Layer B is more preferably free of organic solvents and water.

<Thickness>
Although the thickness of the layer B is not particularly limited, it is preferably 0.1 μm or more, more preferably 1 μm or more, and even more preferably 5 μm or more from the viewpoint of better wiring misalignment suppression performance. Moreover, the thickness of the layer B is preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less, from the viewpoint that the dielectric loss tangent of the laminate is superior.
In addition, the ratio of the thickness of layer B to the thickness of layer A (thickness of layer B/thickness of layer A) is preferably 0.01 to 0.8, and 0.02, in terms of achieving a well-balanced effect of the present invention. ~0.4 is more preferred.
In addition, the thickness of the layer B means the thickness of the layer B formed on one surface of the layer A.

[Intermediate layer]
The laminate may have an intermediate layer between layer A and layer B, if desired.
As the intermediate layer, a known adhesive layer used in the production of wiring boards such as copper-clad laminates can be used, for example, a layer made of a cured adhesive composition containing a known binder resin.
Examples of binder resins include (meth)acrylic resin, polyvinyl cinnamate, polycarbonate, polyimide, polyamideimide, polyesterimide, polyetherimide, polyetherketone, polyetheretherketone, polyethersulfone, polysulfone, polypara Xylene, polyester, polyvinyl acetal, polyvinyl chloride, polyvinyl acetate, polyamide, polystyrene, polyurethane, polyvinyl alcohol, cellulose acylate, fluorinated resin, liquid crystal polymer, syndiotactic polystyrene, silicone resin, epoxy silicone resin, phenolic resin, Examples include alkyd resins, epoxy resins, maleic resins, melamine resins, urea resins, aromatic sulfonamides, benzoguanamine resins, and silicone elastomers.

The thickness of the intermediate layer is preferably 3 μm or less, and more preferably 1 μm or less, in order to enhance the effects of the present invention. Although the lower limit is not particularly limited, it is preferably 0.01 μm or more, more preferably 0.1 μm or more, from the viewpoint of better adhesion between Layer A and Layer B.

The laminate may have layers other than layer A, layer B, and intermediate layer, if necessary. Other layers include antirust layers and heat resistant layers.

[Physical properties of laminate]
The thickness of the laminate including layer A and layer B is not particularly limited, but is preferably 5 to 1000 μm, more preferably 10 to 500 μm, even more preferably 20 to 300 μm.
The thickness of the laminate can be measured according to the method for measuring the thickness of layer A described above.

[Method for manufacturing laminate]
The method for producing the laminate is not particularly limited, and for example, the step of producing a polymer film using the composition containing the components constituting the layer A (hereinafter also referred to as “step A”), and the step A. A laminate having a layer A and a layer B disposed on at least one surface of the layer A, wherein the layer B is formed on at least one surface of the coated polymer film using the composition for forming the layer B. (hereinafter also referred to as “step B”).
A method for manufacturing a laminate having steps A and B will be described below.

<Process A>
The process A for producing a polymer film is not particularly limited, but for example, a pelletizing process of kneading the components constituting the layer A described above to obtain pellets, and a film forming process of forming a resin film using the pellets. and a method comprising:
The process A will be described in detail below.

(Pelletization process)
(1) Form of raw material The liquid crystal polymer used for film formation can be used as it is in the form of pellets, flakes, or powder. For the purpose, it is preferable to use pellets obtained by kneading and pelletizing one or more raw materials (meaning at least one of a polymer and other components; the same shall apply hereinafter) using an extruder.

(2) Substitute for Drying by Drying or Vent When pelletizing, it is preferable to dry the liquid crystal polymer and other components in advance. Drying methods include circulating heated air with a low dew point and dehumidifying by vacuum drying. Vacuum drying or drying using an inert gas is particularly preferable for a resin that is easily oxidized.

(3) Raw material supply method The raw material supply method may be a method of mixing the raw materials in advance before kneading and pelletizing, and supplying the raw materials separately so that the ratio is constant in the extruder. or a combination of the two.

(4) Atmosphere of Extrusion Process During melt extrusion, it is preferable to prevent heat and oxidative deterioration as much as possible within a range that does not interfere with uniform dispersion. It is also effective to reduce the oxygen concentration by These methods may be performed singly or in combination.

(5) Temperature The kneading temperature is preferably lower than the thermal decomposition temperature of the liquid crystal polymer and other components, and is preferably as low as possible within a range where the load on the extruder and deterioration of uniform kneading properties are not a problem. .

(6) Pressure The kneading resin pressure during pelletization is preferably 0.05 to 30 MPa. In the case of a resin that tends to be colored or gelled by shearing, it is preferable to apply an internal pressure of about 1 to 10 MPa in the extruder to fill the extruder with the resin raw material.

(7) Pelletizing method As a pelletizing method, it is common to extruded into a noodle shape, solidify it in water, and then cut it. Pelletization may be performed by a cutting method or a hot cutting method in which the material is cut in a hot state.

(8) Pellet size The pellet size preferably has a cross-sectional area of 1 to 300 mm ² and a length of 1 to 30 mm, and a cross-sectional area of 2 to 100 mm ² and a length of 1.5 to 10 mm. It is more preferable to have

(dry)
(1) Purpose of Drying It is preferable to reduce moisture and volatile matter in the pellets before the melt film formation, and it is effective to dry the pellets. If moisture or volatile matter is contained in the pellets, it not only causes appearance deterioration due to bubble inclusion in the polymer film or reduction in haze, but also deterioration in physical properties due to molecular chain scission of the liquid crystal polymer, or monomer Alternatively, roll staining may occur due to the generation of oligomers. In some cases, depending on the type of liquid crystal polymer used, the formation of oxidized crosslinked products during melt film formation can be suppressed by removing dissolved oxygen by drying.

(2) Drying method/heating method Regarding the drying method, it is common to use a dehumidifying hot air dryer in terms of drying efficiency and economy, but there are no particular restrictions as long as the desired moisture content is obtained. . Also, there is no problem in selecting a more appropriate method according to the physical properties of the liquid crystal polymer.
Heating methods include pressurized steam, heater heating, far-infrared radiation, microwave heating, and heat medium circulation heating.

(Film forming process)
The film forming process will be described below.

(1) Extrusion Conditions/Material Drying In the melt-plasticizing step of the pellets by an extruder, it is preferable to reduce moisture and volatile matter in the same manner as in the pelletizing step, and it is effective to dry the pellets.

・Material supply method If the materials (pellets) to be fed from the feed port of the extruder are of multiple types, they may be mixed in advance (premix method), or they may be mixed in a certain proportion into the extruder. They may be supplied separately or a combination of the two may be used. Further, in order to stabilize the extrusion, it is common practice to reduce fluctuations in temperature and bulk specific gravity of raw materials fed from a feed port. In terms of plasticization efficiency, the raw material temperature is preferably high as long as it does not stick and block the supply port, and in the case of an amorphous state {glass transition temperature (Tg) (° C.) ° C} to {Tg (° C)-1° C}, and in the case of a crystalline resin, the range of {melting point (Tm) (° C)-150° C} to {Tm (° C)-1° C} is preferable. Warming or keeping warm is performed. From the viewpoint of plasticization efficiency, the bulk specific gravity of the raw material is preferably 0.3 times or more, more preferably 0.4 times or more, that of the molten state. When the bulk specific gravity of the raw material is less than 0.3 times the specific gravity of the molten state, it is also preferable to perform a processing treatment such as compressing the raw material to form a pseudo-pellet.

・Atmosphere of extrusion process The atmosphere during melt extrusion must prevent heat and oxidative deterioration as much as possible within a range that does not hinder uniform dispersion, as in the pelletizing process. It is also effective to reduce the oxygen concentration in the extruder using injection and a vacuum hopper, and to provide a vent port in the extruder and reduce the pressure with a vacuum pump. These decompression and inert gas injection may be performed independently or in combination.

· Rotation speed The rotation speed of the extruder is preferably 5 to 300 rpm, more preferably 10 to 200 rpm, and even more preferably 15 to 100 rpm. If the rotational speed is equal to or higher than the lower limit value, the residence time is shortened, the decrease in molecular weight due to thermal deterioration can be suppressed, and discoloration can be suppressed. If the rotation speed is equal to or lower than the upper limit, it is possible to suppress the breaking of molecular chains due to shearing, thereby suppressing the decrease in molecular weight and the increase in crosslinked gel. It is preferable to select an appropriate number of revolutions from the viewpoints of uniform dispersion and heat deterioration due to extended residence time.

- Temperature Barrel temperature (supply part temperature _T1 °C _, compression part temperature _T2 °C, metering part temperature _T3 °C) is generally determined by the following method. When pellets are melt-plasticized by an extruder at a target temperature of T°C, the metering section temperature _T3 is set to T±20°C in consideration of the shear heating value. At this time, _T2 is set within the range of _T3 ±20° C. in consideration of extrusion stability and thermal decomposition of the resin. T ₁ is generally {T ₂ (° C.) −5° C.} to {T ₂ (° C.) −150° C.} to ensure friction between the resin and the barrel, which is the driving force (feed force) for feeding the resin, Select the optimum value from the viewpoint of compatibility with preheating in the feed section. In the case of a normal extruder, it is possible to subdivide the T ₁ to T ₃ zones and set the temperature. It is possible to convert At this time, T is preferably lower than the thermal deterioration temperature of the resin, and when the thermal deterioration temperature is exceeded due to the shear heat generated by the extruder, the shear heat is generally removed by cooling. Also, in order to achieve both improved dispersibility and thermal deterioration, it is effective to melt and mix the resin at a relatively high temperature in the first half of the extruder and lower the resin temperature in the second half.

· Pressure The resin pressure in the extruder is generally 1 to 50 MPa, preferably 2 to 30 MPa, more preferably 3 to 20 MPa in terms of extrusion stability and melt uniformity. If the pressure in the extruder is 1 MPa or more, the filling rate of the melt in the extruder is sufficient, so that the instability of the extrusion pressure and the generation of foreign substances due to the generation of stagnant portions can be suppressed. Moreover, if the pressure in the extruder is 50 MPa or less, excessive shear stress received in the extruder can be suppressed, so thermal decomposition due to an increase in resin temperature can be suppressed.

• Residence time The residence time in the extruder (residence time during film formation) can be calculated from the volume of the extruder portion and the discharge volume of the polymer, as in the pelletizing step. The residence time is preferably 10 seconds to 60 minutes, more preferably 15 seconds to 45 minutes, even more preferably 30 seconds to 30 minutes. If the residence time is 10 seconds or more, melt plasticization and dispersion of other ingredients are sufficient. A residence time of 30 minutes or less is preferable in terms of suppressing deterioration of the resin and discoloration of the resin.

(filtration)
・Type, purpose of installation, structure It is common to install filtration equipment at the outlet of the extruder to prevent damage to the gear pump due to foreign matter contained in the raw material and to extend the life of the fine pore size filter installed downstream of the extruder. used for purposes. It is preferable to perform a so-called breaker plate type filtration in which a mesh filter medium is used in combination with a strong reinforcing plate having a high open area ratio.

- Mesh size, filtration area The mesh size is preferably 40 to 800 mesh, more preferably 60 to 700 mesh, and even more preferably 100 to 600 mesh. If the mesh size is 40 mesh or more, it is possible to sufficiently prevent foreign matter from passing through the mesh. Further, if the mesh size is 800 mesh or less, it is possible to suppress an increase in filtration pressure increase speed and reduce the mesh replacement frequency. In addition, from the point of view of filtration accuracy and strength retention, a plurality of types of filter meshes with different mesh sizes are often used in combination. In addition, the filter mesh can be reinforced by using a breaker plate because it is possible to increase the filter opening area and maintain the strength of the mesh. The opening ratio of the breaker plate used is often 30-80% in terms of filtration efficiency and strength.
In addition, the screen changer is often used with the same diameter as the barrel diameter of the extruder, but in order to increase the filtration area, a tapered pipe is used to use a filter mesh with a larger diameter, or A plurality of breaker plates may be used by branching the flow path. The filtration area is preferably selected based on a flow rate of 0.05 to 5 g/cm ² per second, more preferably 0.1 to 3 g/cm ² , and even more preferably 0.2 to 2 g/cm ² .
The trapping of foreign matter causes the filter to become clogged and the filtering pressure increases. In that case, it is necessary to stop the extruder and replace the filter, but a type in which the filter can be replaced while continuing extrusion can also be used. In addition, as a countermeasure against an increase in filtration pressure due to trapping of foreign matter, it is also possible to use a filter having a function of lowering the filtration pressure by washing and removing foreign matter trapped in the filter by reversing the flow path of the polymer.

(die)
・Type, structure, and material Foreign matter is removed by filtration, and the melted resin whose temperature is equalized by a mixer is continuously sent to a die. The die is not particularly limited as long as it is designed so that the molten resin stays little, and any type of generally used T die, fish tail die, and hanger coat die can be used. Among these, the hanger coat die is preferable in terms of thickness uniformity and less retention.

・Multi-layer film production A single-layer film production equipment with low equipment cost is used for the production of polymer films. Alternatively, a multi-layer film-forming apparatus may be used to produce a polymer film having functional layers such as Layer B, a surface protective layer, an adhesive layer, an easy-adhesive layer, and/or an antistatic layer. Specific examples include a method of forming multiple layers using a feed block for multiple layers, and a method of using a multi-manifold die. Although it is preferable to laminate the functional layer thinly on the surface layer, the layer ratio is not particularly limited.

- Cast The film-forming step preferably includes a step of supplying a raw material resin in a molten state from a supply means, and a step of forming a film by landing the raw resin in a molten state on a cast roll. It may be cooled and solidified and wound as it is as a polymer film, or it may be passed between a pair of pressing surfaces and continuously pressed to form a film.
At that time, there is no particular limitation on the means for supplying the raw material resin (melt) in a molten state. For example, as a specific means for supplying the melt, an extruder that melts and extrudes a raw resin containing a liquid crystal polymer into a film may be used, or an extruder and a die may be used, and the raw resin is once solidified. It may be formed into a film by heating, melted by heating means to form a melt, and supplied to the film forming process.
When a molten resin extruded from a die in the form of a sheet is pressed by a device having a pair of pressing surfaces, not only can the surface morphology of the pressing surfaces be transferred to the surface of the polymer film, but also the composition containing the liquid crystal polymer can be transferred. Orientation can be controlled by applying elongation deformation.

・Methods and types of film formation Among the methods for forming a film from raw resin in a molten state, two rolls (for example, a touch roll and a chill roll) are used in terms of the ability to apply a high clamping force and the excellent surface shape of the polymer film. ) is preferably passed through. In this specification, when there are a plurality of cast rolls for conveying the melt, the cast roll closest to the most upstream liquid crystal polymer supply means (for example, die) is referred to as a chill roll. In addition, a method of pressing between metal belts or a method of combining rolls and metal belts can also be used. In some cases, in order to increase the adhesion to the roll or metal belt, it is possible to use a combination of film forming methods such as an electrostatic application method, an air knife method, an air chamber method, and a vacuum nozzle method on a cast drum. can also
In addition, when obtaining a polymer film with a multilayer structure, it is preferable to obtain it by pressing a raw material resin containing a molten polymer extruded in multiple layers from a die. It is also possible to obtain a multi-layered polymer film by introducing it into the pressing section. At this time, by changing the peripheral speed difference of the pinching part or the orientation axis direction, a polymer film having a different tilt structure in the thickness direction can be obtained. It is also possible to obtain
Further, deformation may be given by, for example, periodically vibrating the touch roll in the TD direction at the time of pressing.

・Molten polymer temperature The discharge temperature (resin temperature at the outlet of the supply means) should be (Tm-10) ° C. to (Tm + 40) ° C. from the viewpoint of improving the moldability of the liquid crystal polymer and suppressing deterioration. is preferred. As a standard of melt viscosity, 50 to 3500 Pa·s is preferable.
It is preferable that the cooling of the molten polymer between the air gaps is as small as possible, and it is preferable to reduce the temperature drop due to cooling by increasing the film forming speed, shortening the air gap, or the like.

- Touch roll temperature It is preferable to set the temperature of the touch roll below the Tg of the liquid crystal polymer. If the temperature of the touch roll is equal to or lower than the Tg of the liquid crystal polymer, adhesion of the molten polymer to the roll can be suppressed, and the appearance of the polymer film is improved. For the same reason, it is preferable to set the chill roll temperature below the Tg of the liquid crystal polymer.

・Film production procedure In the film production process, in terms of the film production process and quality stabilization, the molten polymer discharged from the die is landed on a cast roll and formed into a film, which is then cooled and solidified to form a polymer. It is preferable to form the film by winding it up as a film.
In the case of pinching the molten polymer, the molten polymer is passed between a first pinching surface and a second pinching surface set to a predetermined temperature, cooled and solidified, and wound up as a polymer film.

(Stretching process, heat relaxation treatment, heat setting treatment)
Furthermore, after forming an unstretched polymer film by the above method, stretching and/or heat relaxation treatment or heat setting treatment may be performed continuously or discontinuously. For example, each step can be carried out by combining the following (a) to (g). Further, the order of longitudinal stretching and transverse stretching may be reversed, each step of longitudinal stretching and transverse stretching may be performed in multiple stages, and each step of longitudinal stretching and transverse stretching may be combined with oblique stretching or simultaneous biaxial stretching. may
(a) Lateral stretching (b) Lateral stretching → Thermal relaxation treatment (c) Longitudinal stretching (d) Longitudinal stretching → Thermal relaxation treatment (e) Longitudinal (horizontal) stretching → Lateral (longitudinal) stretching (f) Longitudinal (horizontal) stretching → Lateral (vertical) stretching → Thermal relaxation treatment (g) Lateral stretching → Thermal relaxation treatment → Longitudinal stretching → Thermal relaxation treatment Hereinafter, the unstretched polymer film and the stretched polymer film are collectively referred to simply as “film”.

-Longitudinal stretching Longitudinal stretching can be achieved by making the peripheral speed on the exit side faster than the peripheral speed on the inlet side while heating between two pairs of rolls. From the viewpoint of suppressing curling, it is preferable that the front and back surfaces of the film to be stretched are at the same temperature. The stretching temperature here is defined as the temperature on the lower side of the film surface. The longitudinal stretching process may be carried out in one step or in multiple steps. Preheating of the unstretched film is often performed by passing it through a temperature-controlled heating roll, but in some cases, the unstretched film can be heated using a heater. In order to prevent the film to be stretched from adhering to the roll, a ceramic roll or the like with improved adhesion may be used.

- Lateral stretching Normal lateral stretching can be adopted as the lateral stretching step. That is, the normal transverse stretching includes a stretching method in which both ends in the width direction of a film to be stretched are held with clips, and the clips are widened while being heated in an oven using a tenter. Regarding the lateral stretching step, for example, Japanese Utility Model Laid-Open No. 62-035817, Japanese Patent Application Laid-Open No. 2001-138394, Japanese Patent Application Laid-Open No. 10-249934, Japanese Patent Application Laid-Open No. 6-270246, Japanese Utility Model Application Laid-Open No. 4-030922, and , JP-A-62-152721 can be used, and these methods are incorporated herein.

The draw ratio in the width direction of the film in the transverse drawing step (lateral draw ratio) is preferably 1.2 to 6 times, more preferably 1.5 to 5 times, and still more preferably 2 to 4 times. Moreover, when longitudinal stretching is performed, the lateral draw ratio is preferably larger than the longitudinal draw ratio.
The stretching temperature in the lateral stretching step can be controlled by blowing air at a desired temperature into the tenter. For the same reason as in longitudinal stretching, the film temperature may be the same or different on the front and back surfaces. Stretching temperature as used herein is defined as the temperature on the lower side of the film surface. The transverse stretching process may be carried out in one step or in multiple steps. Further, when transverse stretching is carried out in multiple stages, it may be carried out continuously, or may be carried out intermittently by providing a zone in which the width is not widened. For such lateral stretching, besides the usual lateral stretching in which the clip is widened in the width direction in a tenter, the following stretching method in which the clip is gripped and widened in the same manner as above can also be applied.

・Diagonal stretching In the diagonal stretching process, the clip is widened in the horizontal direction as in the normal horizontal stretching. As the diagonal stretching step, for example, JP-A-2002-022944, JP-A-2002-086554, JP-A-2004-325561, JP-A-2008-023775, and JP-A-2008-110573 The methods described can be used.

- Simultaneous biaxial stretching Simultaneous biaxial stretching is a process of expanding the width of a clip in the horizontal direction and simultaneously stretching or shrinking it in the vertical direction, as in normal lateral stretching. Examples of simultaneous biaxial stretching include, for example, Japanese Utility Model Laid-Open Publication No. 55-093520, Japanese Laid-Open Patent Publication No. 63-247021, Japanese Laid-Open Patent Publication No. 6-210726, Japanese Laid-Open Patent Publication No. 6-278204, and Japanese Laid-Open Patent Publication 2000-334832. , JP 2004-106434, JP 2004-195712, JP 2006-142595, JP 2007-210306, JP 2005-022087, JP 2006-517608, and , the method described in JP-A-2007-210306 can be used.

・Heat treatment to improve bowing (axis misalignment) In the horizontal stretching process, the edges of the film are held by clips. As a result, the characteristics in the width direction are distributed. If a straight line is drawn in the horizontal direction on the surface of the film before the heat treatment process, the straight line on the surface of the film after the heat treatment process will have an arcuate shape with the center part recessed toward the downstream. This phenomenon is called the bowing phenomenon, and causes the isotropy and the uniformity in the width direction of the film to be disturbed.
As a method for improvement, preheating is performed before lateral stretching, or heat setting is performed after stretching to reduce the variation in the orientation angle due to bowing. Either one of preheating and heat setting may be performed, but it is more preferable to perform both. These preheating and heat setting are preferably carried out by gripping with a clip, that is, preferably carried out continuously with stretching.

The preheating temperature is preferably about 1 to 50°C higher than the stretching temperature, more preferably 2 to 40°C higher, even more preferably 3 to 30°C higher. The preheating time is preferably 1 second to 10 minutes, more preferably 5 seconds to 4 minutes, even more preferably 10 seconds to 2 minutes.
It is preferable to keep the width of the tenter substantially constant during preheating. Here, "approximately" refers to ±10% of the width of the unstretched film.

The heat setting temperature is preferably 1 to 50°C lower than the stretching temperature, more preferably 2 to 40°C lower, and even more preferably 3 to 30°C lower. Temperatures below the stretching temperature and below the Tg of the liquid crystal polymer are particularly preferred.
The heat setting time is preferably 1 second to 10 minutes, more preferably 5 seconds to 4 minutes, even more preferably 10 seconds to 2 minutes. During heat setting, it is preferable to keep the width of the tenter substantially constant. Here, "almost" refers to 0% of the tenter width after stretching (the same width as the tenter width after stretching) to -30% (30% smaller than the tenter width after stretching=shrinkage width). Other known methods include the methods described in JP-A-1-165423, JP-A-3-216326, JP-A-2002-018948, and JP-A-2002-137286.

- Thermal relaxation treatment After the stretching step, a thermal relaxation treatment may be performed to shrink the film by heating the film. The thermal relaxation treatment can reduce the thermal shrinkage of the polymer film when the laminate is used. The thermal relaxation treatment is preferably performed at least one timing after film formation, after longitudinal stretching, and after transverse stretching.
The thermal relaxation treatment may be continuously performed online after stretching, or may be performed offline after winding after stretching. The temperature of the thermal relaxation treatment is, for example, the glass transition temperature Tg or higher and the melting point Tm or lower of the liquid crystal polymer. If there is concern about oxidative deterioration of the polymer film, thermal relaxation treatment may be performed in an inert gas such as nitrogen gas, argon gas, or helium gas.

(annealing treatment)
In the step A, it is preferable to perform an annealing treatment by heating the film after stretching the film, in terms of better electrical properties.
The heating temperature in the annealing treatment is preferably {Tm-200}°C or higher, more preferably {Tm-100}°C or higher, and still more preferably {Tm-50}°C or higher, where Tm (°C) is the melting point of the liquid crystal polymer. The upper limit of the heating temperature in the annealing treatment is preferably {Tm+50}° C. or less, more preferably {Tm+30}° C. or less.
Alternatively, the heating temperature in the annealing treatment is preferably 240° C. or higher, more preferably 255° C. or higher, and even more preferably 270° C. or higher. The upper limit is preferably 370°C or lower, more preferably 350°C or lower.

Heating means used for the annealing treatment include a hot air drying oven and an infrared heater, and the infrared heater is preferable in that a film having a desired melting peak area can be produced in a short time. Moreover, pressurized steam, microwave heating, and heat medium circulation heating may be used as the heating means.
The annealing treatment time can be appropriately adjusted according to the type of liquid crystal polymer, the heating means and the heating temperature. When using an infrared heater, it is preferably 1 to 120 seconds, more preferably 3 to 90 seconds. When using a hot air drying oven, the drying time is preferably 1 to 14 hours, more preferably 2 to 10 hours.

(surface treatment)
It is preferable to subject the polymer film to a surface treatment because the adhesion between the polymer film and wiring or other layers made of metal such as copper foil and copper plating layer can be further improved. Surface treatments include, for example, glow discharge treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, and acid or alkali treatment. The glow discharge treatment referred to here may be low-temperature plasma generated under a low-pressure gas of 10 ⁻³ to 20 Torr, and plasma treatment under atmospheric pressure is also preferable.
Glow discharge treatment is performed using a plasma-excitable gas. Plasma-excitable gas is a gas that is plasma-excited under the above conditions, for example, argon, helium, neon, krypton, xenon, nitrogen, carbon dioxide, fluorocarbons such as tetrafluoromethane, and mixtures thereof is mentioned.

It is also useful to subject the polymer film to aging treatment at a temperature below the Tg of the liquid crystal polymer in order to improve the mechanical properties, thermal dimensional stability, or appearance of the wound polymer film.
In addition, the polymer film may be further subjected to a step of compressing and/or stretching the polymer film with heated rolls after passing through the film-forming step to further improve the smoothness of the polymer film.

In the above manufacturing method, the case where the polymer film is a single layer is described, but the polymer film may have a laminated structure in which multiple layers are laminated.

<Step B>
Step B is a step of forming a layer B on the polymer film produced in step A using a composition for forming layer B, thereby producing a laminate having a layer A and a layer B made of a polymer film. be.

In step B, for example, the composition for forming layer B is applied to at least one surface of the polymer film produced in step A, and the coating film is dried and / or cured as necessary to form a film on the polymer film. a step of forming a layer B in the above.

Examples of the composition for forming layer B include compositions containing components constituting layer B, such as the resin and reactive compound described above. Since the components constituting the layer B are as described above, the description thereof will be omitted.

A solvent may be used individually by 1 type, or may use 2 or more types.
The content of the solvent contained in the layer B forming composition is preferably 0.02% by mass or less, more preferably 0.01% by mass or less, relative to the total mass of the layer B forming composition. The lower limit is not particularly limited, and may be 0% by mass.
The solid content of the composition for forming layer B is preferably 99.98% by mass or more, more preferably 99.99% by mass, based on the total mass of the composition for forming layer B. The upper limit is not particularly limited, and may be 100% by mass.
As used herein, the "solids" of the composition means the components excluding solvent and water. That is, the solid content of the layer B-forming composition means the components constituting the layer B such as the above-mentioned resin and reactive compound.

The method for attaching the layer B-forming composition onto the polymer film is not particularly limited, and examples thereof include bar coating, spray coating, squeegee coating, flow coating, spin coating, dip coating, and die coating. , an inkjet method, and a curtain coating method.
When drying the layer B forming composition deposited on the polymer film, the drying conditions are not particularly limited, but the drying temperature is preferably 25 to 200° C., and the drying time is preferably 1 second to 120 minutes.

When the laminate has intermediate layers and/or other layers between layer A and layer B, those layers can be formed according to known methods. The intermediate layer can also be formed by a method according to the above step B.

[Wiring board]
A wiring board of the present invention includes the laminate and a base material with wiring having a base material and wiring. A wiring board having the laminate has a low dielectric loss tangent, suppresses positional deviation of wiring in the in-plane direction, and has excellent electrical characteristics between wirings.

Examples of the wiring board include a wiring board obtained by laminating the laminate and the base material with wiring so that the layer B and the wiring are in contact with each other. The wiring board preferably has at least a layer structure in which a substrate, wiring, layer B and layer A are laminated in this order.
The number of laminates and substrates with wiring included in the wiring board is not limited, and the number of each member may be one or two or more.
The wiring board may have layers or members other than the laminate and the substrate with wiring.

[Base material with wiring]
A substrate with wiring has a substrate and wiring arranged on at least one surface of the substrate.
The substrate and wiring will be described below.

<Base material>
Examples of the substrate include known sheets and films used as substrates for wiring boards. Examples of constituents of the substrate include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polycycloolefin, polycarbonates, (meth)acrylic resins, polyimides, and liquid crystal polymers.
Moreover, as a base material, the film which consists only of the said laminated body and said layer A can also be used.

Although the thickness of the substrate is not particularly limited, it is preferably 5 to 1000 μm, more preferably 10 to 500 μm, even more preferably 20 to 300 μm.
The thickness of the substrate can be measured according to the method for measuring the thickness of the layer A described above.

<Wiring>
The wiring is a member made of a conductive material, and is composed of a region where the conductive member exists and a region where the conductive member does not exist on the surface of the base material. The shape of the wiring in the in-plane direction is appropriately designed according to the use of the wiring board.
Concavities and convexities corresponding to the shape of the wiring are often formed on the wiring-side surface of the substrate with wiring. Even in that case, by laminating the laminate to the substrate with wires so that the layer B whose elastic modulus is within a predetermined range is in contact with the wiring, the wiring displacement is suppressed and the laminate with a low dielectric loss tangent is obtained. can be made.

The shape of the wiring is not particularly limited, and is appropriately selected according to the application of the wiring board.
The thickness of the wiring is not particularly limited, and is appropriately selected according to the application of the wiring board. The thickness of the wiring is, for example, 1 to 100 μm, preferably 2 to 50 μm, more preferably 5 to 40 μm, in terms of conductivity and economy.

Examples of components that make up wiring include metals used for electrical connections. Such metals include, for example, copper, gold, silver, nickel, aluminum, and alloys containing any of these metals. Alloys include, for example, copper-zinc alloys, copper-nickel alloys, and zinc-nickel alloys.
As the wiring, copper wiring is preferable from the viewpoint of excellent conductivity and workability. Copper wiring is wiring made of copper or a copper alloy containing 95% by mass or more of copper. The copper wiring includes, for example, a rolled copper foil produced by a rolling method, and a copper wiring obtained by patterning a copper foil such as an electrolytic copper foil produced by an electrolysis method. Chemical treatment such as acid cleaning may be applied to the metal material forming the wiring.

The method of forming the wiring is not particularly limited, for example, a method of forming wiring by laminating a polymer film and a metal foil by thermocompression bonding and then subjecting the formed metal layer to an etching treatment or the like. Alternatively, a wiring having a predetermined shape may be directly formed on the surface of the polymer film by a vapor phase method such as a sputtering method, an ion plating method, a vacuum deposition method, or a known method such as a wet plating method. good.

The RSm of the surface of the wiring included in the substrate with wiring is preferably 1.2 μm or less, more preferably 0.9 μm or less. Although the lower limit is not particularly limited, it is preferably 0.1 μm or more.
Examples of metal foils used to fabricate wiring having a surface RSm within the above range include non-roughened copper foils and the like, which are commercially available.

The RSm of the wiring surface can be measured by a method conforming to JIS B0601:2001. Specifically, it is as follows.
After the wiring exposed on the surface of the base material with wiring is embedded in resin for observation, the embedded wiring is cut along the thickness direction. The resulting cross section is observed using a scanning electron microscope (SEM) (magnification: 50,000 times). The cross-sectional curve of the interface between the wiring and the resin layer is measured by tracing the interface between the wiring and the resin layer in the obtained observed image over a measurement length of 2000 nm by image processing. Furthermore, a roughness curve is obtained from the obtained cross-sectional curve using a roughness curve filter with a cutoff value of 700 nm (higher wavelength side) and a cutoff value of 10 nm (lower wavelength side). This roughness curve is measured for 10 SEM observation images with different cross-sectional positions, and the length of the roughness curve element at the reference length (= cutoff value on the high wavelength side) is arithmetically averaged. , RSm of the surface of the wiring is obtained.

The wiring board may have an adhesive layer such as a bonding sheet or an adhesive layer between the laminate and the base material with wiring, but the dielectric loss tangent of the wiring board can be further reduced. Instead, it is preferable that the layer B and the wiring are in direct contact with each other.

[Method for manufacturing wiring board]
The method of manufacturing the wiring substrate is not particularly limited, and for example, a method of manufacturing a wiring substrate by laminating a laminate and a base material with wiring so that the layer B faces the wiring, and then thermocompression bonding the two. are mentioned.
The method and conditions for thermocompression bonding the laminate and the substrate with wiring are not particularly limited, and are appropriately selected from known methods and conditions. Among them, the temperature condition for thermocompression bonding is preferably 100 to 300° C., and more preferably 140 to 200° C. in order to exhibit the effects of the present invention more preferably. The pressure condition for thermocompression bonding is preferably 0.1 to 20 MPa. The treatment time for the crimping treatment is preferably 0.001 to 1.5 hours.

A second laminate may be further attached to the wiring substrate produced by attaching the laminate to the base material with wiring. For example, after forming the second wiring on the surface of the layer A exposed in the wiring board, a second laminate having the second layer A and the second layer B is formed between the second wiring and the second layer. A wiring board having a layer structure in which the substrate/wiring/layer B/layer A/wiring/layer B/layer A is arranged in this order is obtained by laminating the second wiring so that the layer B faces the second wiring. . Further, the wiring-equipped laminate having the second wiring, the first layer A and the first layer B is replaced with the wiring-equipped substrate having the first wiring such that the first layer B and the first wiring are opposed to each other. After lamination to produce a first wiring board, a second laminate having a second layer A and a second layer B is attached to the first layer so that the second layer B and the second wiring face each other. A wiring board having a layer structure in which substrate/wiring/layer B/layer A/wiring/layer B/layer A is arranged in this order can also be obtained.
The method for forming the second wiring on the surface of the layer A of the wiring substrate or laminate is not particularly limited, and can be formed by the method described as the method for forming the wiring of the substrate with wiring.

[Use of wiring board]
Examples of applications of wiring boards include wiring boards such as laminated circuit boards, flexible laminates, and flexible printed circuit boards (FPC). The wiring board is particularly preferably used as a high-speed communication board.

The present invention will be described more specifically below with reference to examples. The materials, amounts used, ratios, processing details, and processing procedures shown in the following examples can be changed as appropriate without departing from the gist of the present invention. Accordingly, the present invention is not limited to the embodiments shown in the examples below. "Parts" and "%" are based on mass unless otherwise specified.

[raw materials]
(liquid crystal polymer)
LCP1: A polymer synthesized based on Example 1 of JP-A-2019-116586 (melting point Tm: 320° C., corresponding to a thermotropic liquid crystal polymer).
LCP2: "Laperos A-950" manufactured by Polyplastics (melting point Tm: 280°C, corresponding to thermotropic liquid crystal polymer).
LCP1 is a repeating unit derived from 6-hydroxy-2-naphthoic acid, a repeating unit derived from 4,4'-dihydroxybiphenyl, a repeating unit derived from terephthalic acid, and a repeating unit derived from 2,6-naphthalenedicarboxylic acid. Consists of repeating units.
LCP2 is composed of repeating units derived from parahydroxybenzoic acid and repeating units derived from 6-hydroxy-2-naphthoic acid.

(Composition for forming layer B)
・ Resin 1: Low density polyethylene (“CL-2080”, manufactured by Sumitomo Seika Co., Ltd.)
・ Resin 2: Styrene-ethylene-butylene-styrene copolymer ("Tuftec (registered trademark) H1221", manufactured by Asahi Kasei Corporation)
- Compound 1: N,N-diglycidyl-4-glycidyloxyaniline (manufactured by Sigma-Aldrich)
・Solvent: Toluene

[Example 1]
A laminate having layers A and B was produced by the method shown below.

[Preparation of layer A]
The liquid crystal polymer LCP1 was supplied into the cylinder from the supply port of a single-screw extruder with a screw diameter of 60 mm, and heated and kneaded. LCP1 in a molten state was discharged from a die with a width of 750 mm onto a rotating cast roll as a film, solidified by cooling, and stretched as desired to obtain a film with a thickness of 50 μm.
The heating and kneading temperature, the ejection speed when ejecting LCP1, the clearance of the die lip, and the peripheral speed of the cast roll were each adjusted within the following ranges.
・Temperature for heating and kneading: 270 to 350°C
・Clearance: 0.01 to 5mm
・Discharge speed: 0.1 to 1000mm/sec
・Peripheral speed of cast roll: 0.1 to 50 m/min

Then, the film was annealed by introducing it into a hot air drying oven set at 270° C. and heating for 10 hours.
The annealed film was conveyed while being guided by rollers, and was picked up by nip rollers to obtain a polymer film.

[Formation of Layer B]
The resin 1, the compound 1, and the solvent were mixed and stirred to obtain a composition B1 for forming a layer B. At this time, the total content of Resin 1 and Compound 1 was 5 parts by mass when the total mass of Composition B1 was 100 parts by mass.
The resulting composition B1 was applied to the surface of the produced polymer film using an applicator (clearance: 250 μm) to form a coating film. The coating film was dried at 130° C. for 1 hour. The application of the composition B1 and the drying of the applied film were repeated to form a layer B having a thickness of 20 μm, and a laminate of Example 1 having layers A and B was produced. The content of Compound 1 in Layer B is shown in Table 1 below. The balance of Compound 1 in Layer B is Resin 1.

[Examples 2 to 6, 8 and 9, and Comparative Example 2]
As shown in Table 1, the content of compound 1, the thickness of layer B, the type of resin constituting layer B, and the type of liquid crystal polymer in the composition for forming layer B were changed, and annealing Laminates of Examples 2 to 6, 8 and 9, and Comparative Example 2 were produced according to the method described in Example 1, except that the treatment conditions were changed.
In Comparative Example 2, a polymer film was produced according to the method described in Example 1, except that the formed film was annealed in a hot air drying oven set at 270° C. and heated for 1 hour.

[Example 7]
A polymer film was prepared according to the method described in Example 1 [Preparation of Layer A].
After corona-treating the surface of the produced polymer film under conditions of a discharge amount of 700 W min/m ² , the following intermediate layer forming solution is applied to the corona-treated surface with an applicator and dried. An intermediate layer was produced by The thickness of the intermediate layer was 2 μm.
The intermediate layer forming solution contains a thermoplastic polyimide resin (25% by mass), cyclohexanone (solvent) (65% by mass), toluene (solvent) (9% by mass), and an epoxy group-containing cross-linking agent (1% by mass). include.

A layer B having a thickness of 20 μm was formed on the surface of the formed intermediate layer opposite to the polymer film according to the method described in Example 1 [Formation of layer B]. Thus, a laminate of Example 7 having layer A, intermediate layer and layer B was produced.

[Comparative Example 1]
A polymer film was prepared according to the method described in Example 1 [Preparation of Layer A]. Using the produced polymer film as the film of Comparative Example 1, an evaluation test described later was performed.

[Measurement, evaluation]
The following measurements and evaluations were performed on the resin film (corresponding to the resin layer in the laminate) produced by the production method of each of the above examples.

<Melting peak area of layer A>
The center portion of layer A was sampled from the laminate produced in each example, and the melting peak area of the obtained sample was measured using a differential scanning calorimeter ("DSC-60A" manufactured by Shimadzu Corporation). Specifically, the sample was heated from 25° C. to 380° C. at a heating rate of 10° C./min, and the endothermic heat value of the sample was measured. A curve (DSC curve) showing changes in the measured endothermic heat value. It was created. The area of the endothermic peak surrounded by the endothermic peak (melting peak) and the baseline of the created DSC curve was calculated to obtain the melting peak area (unit: J/g) of the sample. The endothermic peak and baseline in the DSC curve were specified based on JIS K7121.

<Elastic modulus>
The elastic modulus of layer B of the laminates produced in Examples 1 to 9 and Comparative Example 2 was measured by the following method.
A cut surface was produced by cutting the laminate produced in each example along the thickness direction. In the cut surface of the sample of the laminate having the cut surface, the elastic modulus at the intermediate position in the thickness direction of the layer B from one surface to the other surface was increased to 160 ° C. using a heater attached to the nanoindenter described below. It was measured by the nanoindentation method while heating.
The elastic modulus was measured using a nanoindenter (“TI-950”, manufactured by HYSITRON) and a Berkovich indenter under the conditions of a load of 500 μN, a load time of 10 seconds, a holding time of 5 seconds, and an unloading time of 10 seconds. 10 points were measured for each position. The arithmetic average value of 10 points was made into each elastic modulus (unit: MPa).
As a result of measurement according to the above measurement method, the elastic modulus of the film of Comparative Example 1 was 800 MPa.

<Dielectric loss tangent of laminate>
The central portion of the laminate produced in each example was sampled, and a split cylinder type resonator ("CR-728" manufactured by Kanto Denshi Applied Development Co., Ltd.) and a network analyzer (Keysight N5230A) were used to measure temperature at 20°C and humidity at 50°C. The dielectric loss tangent was measured in a frequency band of 28 GHz in an environment of % RH.
From the measured values obtained, the dielectric loss tangent of each laminate was evaluated based on the following evaluation criteria.

(Dielectric loss tangent evaluation standard)
A: less than 0.0010.
B: 0.0010 or more and less than 0.0015.
C: 0.0015 or more and less than 0.0020.
D: 0.0020 or more.

<Wiring deviation>
The laminate prepared in each example was cut into a size of 15 cm × 15 cm, and a rolled copper foil (thickness 18 μm, surface roughness Ra 0.9 μm) was laminated on the surface of the layer A side of the laminate, and one side was copper-clad. A laminate sample was produced. Next, a mask layer was laminated on the surface of one of the copper layers of the above samples, and the mask layer was pattern-exposed and then developed to form a mask pattern. Only the surface of the sample on the mask pattern side is immersed in a 40% iron (III) chloride aqueous solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., grade 1) to etch the copper layer where the mask pattern is not laminated. The pattern was peeled off to form a copper wiring (microstrip line). The size of the copper wiring was 10 cm long and 105 μm wide. Thus, a sample having a copper wiring formed on one surface was obtained.

Two samples (a, b) were prepared, and the surface of the sample (a) on the side of the copper wiring and the surface of the sample (b) on which the copper wiring was not formed were in contact, and the surfaces of the respective copper wirings Samples (a) and (b) were laminated such that the positions of the .
The resulting multilayer laminate was introduced between a pair of heated metal rolls provided in a continuous hot press and subjected to thermocompression bonding. At this time, the surface temperature of the heating metal roll was set to 160° C., and the pressure applied to the multilayer laminate was set to 40 kg/cm ² in terms of surface pressure.

The multilayer laminate produced by the above method was cut so as to form a cross section including the lamination direction and perpendicular to the longitudinal direction of each copper wiring. The obtained cut surface was observed using a scanning electron microscope (SEM). In the observed cross-sectional images, the position of the copper wiring of the sample (a) is compared with the position of the copper wiring of the sample (b), and the copper wiring of the sample (b) in the in-plane direction (transverse direction of the copper wiring) The difference in the position of the copper wiring of sample (a) with respect to the position of the wiring was measured.
Based on the measured difference, the wiring misalignment of the copper-clad laminate of the wiring board produced using the laminate of each example was evaluated based on the following evaluation criteria.

(Evaluation standard for wiring misalignment)
A: The ratio of the measured value of the difference to the thickness of the laminate is less than 1%.
B: The ratio of the measured value of the difference to the thickness of the laminate is 1% or more and less than 5%.
C: The ratio of the measured value of the difference to the thickness of the laminate is 5% or more and less than 10%.
D: The ratio of the measured value of the difference to the thickness of the laminate is 10% or more.

<Interlayer adhesion>
Each laminate was cut into strips of 1 cm×5 cm to prepare samples for adhesion evaluation. The delamination strength (unit: N/cm) of the obtained sample was measured with reference to the measuring method described in JIS C 5016-1994. Using a tensile tester (manufactured by IMADA Co., Ltd., digital force gauge ZP-200N), layer B was peeled off at a peel rate of 50 mm per minute in a direction forming an angle of 90° with respect to the layer B removal surface. was measured. It can be evaluated that the higher the measured peel strength, the better the adhesion between the layer A and the layer B in the laminate.

[result]
Table 1 below shows the structure of each layer constituting the laminate produced in each example and each comparative example, and the evaluation results of each laminate.
The "amount (%)" column of "reactive compound" in Table 1 indicates the content (unit: mass%) of the reactive compound with respect to the total solid content of the composition for forming layer B used in each example.

As shown in Table 1, the laminate of the present invention includes a layer A that contains a liquid crystal polymer and has a melting peak area of 0.2 J/g or more as measured by differential scanning calorimetry, and an elastic modulus of 500 MPa at 160 ° C. It was confirmed that the desired effect was exhibited by having the layer B below.

When the content of the reactive compound in layer B is 20% by mass or less, it is confirmed that the dielectric loss tangent of the laminate is more excellent, and when the content of the reactive compound in layer B is 15% by mass or less, the laminate It was confirmed that the dielectric loss tangent of the body was further superior (comparison with Examples 1 to 3).
It was confirmed that when the content of the reactive compound in the layer B was 5% by mass or more, the wiring misalignment suppression performance was more excellent (compare Examples 1 and 4).

It was confirmed that when the thickness of the layer B was 3 μm or more, the wiring misalignment suppression performance was more excellent (comparison with Examples 1 and 6).

It was confirmed that when the layer A contained a liquid crystal polymer containing two or more kinds of repeating units derived from dicarboxylic acid, the dielectric loss tangent of the laminate was superior (comparison with Examples 1 and 9).

Claims (10)

1. a layer A containing a liquid crystal polymer;
   and a layer B disposed on at least one surface of the layer A,
   The melting peak area of the layer A measured by differential scanning calorimetry is 0.2 J / g or more,
   A laminate in which the layer B has an elastic modulus of 500 MPa or less at 160°C.
2. The laminate according to claim 1, wherein the liquid crystal polymer contains two or more repeating units derived from dicarboxylic acid.
3. The liquid crystal polymer comprises a repeating unit derived from 6-hydroxy-2-naphthoic acid, a repeating unit derived from an aromatic diol, a repeating unit derived from terephthalic acid, and a repeating unit derived from 2,6-naphthalenedicarboxylic acid. The laminate according to claim 1, comprising at least one selected from the group consisting of:
4. The laminate according to any one of claims 1 to 3, wherein the layer B has a thickness of 5 to 30 µm.
5. The laminate according to any one of claims 1 to 3, wherein the layer B contains a thermoplastic resin.
6. The layer B is a layer formed using a composition containing a thermoplastic resin and a reactive compound,
   6. The laminate according to claim 5, wherein the content of said reactive compound is 5 to 20% by mass with respect to the total mass of said composition.
7. The laminate according to any one of claims 1 to 3, further comprising an intermediate layer between said layer A and said layer B.
8. A wiring board comprising the laminate according to any one of claims 1 to 3 and a base material with wiring having a base material and wiring.
9. The wiring board according to claim 8, wherein the wiring has a thickness of 5 to 40 µm.
10. The laminated body according to any one of claims 1 to 3 and a wiring-attached base material having a base material and wiring are laminated so that the layer B of the laminated body and the wiring face each other, and the laminated body is laminated. A method for producing a wiring board, comprising: producing a wiring board by thermocompression bonding the body and the wiring-attached base material.