Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B15/00—Layered products comprising a layer of metal
  • B32B15/04—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B15/08—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/02—Physical, chemical or physicochemical properties
  • B32B7/022—Mechanical properties
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/38—Boron-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L25/00—Compositions of, homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Compositions of derivatives of such polymers
  • C08L25/02—Homopolymers or copolymers of hydrocarbons
  • C08L25/04—Homopolymers or copolymers of styrene
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K1/00—Printed circuits
  • H05K1/02—Details
  • H05K1/03—Use of materials for the substrate

Definitions

• This disclosure relates to polymer films and laminates.
• Copper-clad laminates are preferably used as components for circuit boards, and films are preferably used to manufacture copper-clad laminates.
• Japanese Patent Application Laid-Open No. 2022-184736 describes a wiring board in which wiring patterns are embedded and the regions between the wiring patterns arranged in the in-plane direction on the same plane have an elastic modulus of 0.1 MPa or less at 140°C and a dielectric loss tangent of 0.006 or less.
• a copper-clad laminate is manufactured by laminating a copper foil on the surface of a polymer film.
• a wiring board is manufactured by stacking a copper-clad laminate and a wiring substrate so that the polymer film of the copper-clad laminate and the wiring substrate are in contact with each other.
• the polymer film deforms to conform to the steps formed on the surface of the wiring substrate from the viewpoint of adhesion.
• a polymer film having excellent step conformability to a wiring substrate is used for a copper-clad laminate, delamination may occur during the reflow soldering process performed when mounting electronic components. For this reason, there has been a demand for a material that has both step conformability to a wiring substrate and excellent adhesion during reflow soldering (i.e., excellent heat resistance).
• the problem that one embodiment of the present disclosure aims to solve is to provide a polymer film and laminate that have excellent step conformability and heat resistance.
• Means for solving the above problems include the following aspects. ⁇ 1> A layer A and a layer B disposed on at least one surface of the layer A,
• the layer A has a surface roughness Rc of 5 ⁇ m or less on the side on which the layer B is disposed,
• the layer B includes a material a having an elastic modulus of less than 0.10 MPa at 260° C. and a material b having an elastic modulus of 0.10 MPa or more at 260° C., and has an elastic modulus of 500 MPa or less at 25° C. and an elastic modulus of 0.60 MPa or less at 160° C.;
• a polymer film having a dielectric loss tangent of 0.01 or less.
• ⁇ 2> The polymer film according to ⁇ 1>, wherein the material a is an elastomer containing a structural unit derived from styrene.
• the material a is at least one selected from the group consisting of a styrene-ethylene-butylene-styrene block copolymer, a styrene-isobutylene-styrene block copolymer, a styrene-ethylene-propylene-styrene copolymer, a styrene-isoprene-styrene block copolymer, and hydrogenated products thereof.
• the material b is at least one selected from the group consisting of a liquid crystal polymer, a polymer of a compound having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond, and a fluororesin.
• a liquid crystal polymer a polymer of a compound having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond
• a fluororesin ⁇ 5>
• ⁇ 6> The polymer film according to ⁇ 5>, wherein the particles have an average particle size of 4.0 ⁇ m or less.
• ⁇ 7> ⁇ 6> The polymer film according to any one of ⁇ 1> to ⁇ 6>, wherein the layer A has an elastic modulus at 160° C. of more than 0.60 MPa.
• ⁇ 8> A laminate comprising the polymer film according to any one of ⁇ 1> to ⁇ 7> and a metal layer or metal wiring disposed on at least one surface of the polymer film.
• the laminate according to ⁇ 8> comprising a layer B, a layer A, and a metal layer in this order.
• a polymer film and laminate with excellent step conformability and heat resistance are provided.
• the use of "to" indicating a range of values means that the values before and after it are included as the lower limit and upper limit.
• the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages.
• the upper or lower limit value of the numerical range may be replaced with a value shown in the examples.
• an "alkyl group” includes not only an alkyl group that has no substituent (an unsubstituted alkyl group) but also an alkyl group that has a substituent (a substituted alkyl group).
• (meth)acrylic is a term used as a concept including both acrylic and methacrylic
• (meth)acryloyl is a term used as a concept including both acryloyl and methacryloyl.
• the term "process" in this specification includes not only an independent process but also a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved. Furthermore, in the present disclosure, combinations of two or more preferred aspects are more preferred aspects.
• GPC gel permeation chromatography
• the average particle size (e.g., D50) of the particles in this disclosure is measured using a laser diffraction/scattering type particle size distribution analyzer.
• a laser diffraction/scattering type particle size distribution analyzer For example, HORIBA's LA-950V2 is used as the laser diffraction/scattering type particle size distribution analyzer.
• the polymer film according to the present disclosure includes a layer A and a layer B disposed on at least one surface of layer A, wherein layer A has a surface roughness Rc of 5 ⁇ m or less on the side on which layer B is disposed, and layer B includes a material a having an elastic modulus of less than 0.10 MPa at 260° C. and a material b having an elastic modulus of 0.10 MPa or more at 260° C., and has an elastic modulus of 500 MPa or less at 25° C. and an elastic modulus of 0.60 MPa or less at 160° C., and a dielectric loss tangent of 0.01 or less.
• thermocompression bonding When manufacturing a multi-layer copper-clad laminate, copper foil and a polymer film are laminated and then thermocompression bonding is performed, during which heating causes some of the materials contained in the polymer film to become fluid. If pressure distribution occurs during thermocompression bonding, some of the fluid materials move from high pressure areas to low pressure areas, resulting in a layer (fluidized layer) in which the fluid materials are separated.
• the laminate In the reflow soldering process performed when mounting electronic components, the laminate is heated at a high temperature (e.g., 260°C) in a water-containing state due to pretreatment, and it is believed that the moisture becomes supersaturated and diffuses, generating bubble nuclei.
• Patent Document 1 JP 2022-184736 A does not mention that the surface roughness Rc of the side of Layer A where Layer B is disposed is set to 5 ⁇ m or less.
• the polymer film described in Patent Document 1, JP 2022-184736 A has an elastic modulus at 25°C of more than 500 MPa.
• the polymer film according to the present disclosure will be described in detail below.
• the polymer film according to the present disclosure includes a layer A and a layer B disposed on at least one surface of the layer A.
• the layer A and the layer B may be in direct contact with each other, or another layer may be provided between the layer A and the layer B. From the viewpoint of step conformability and heat resistance, it is preferable that the layer A and the layer B are in direct contact with each other.
• Layer B includes a material a having an elastic modulus at 260° C. of less than 0.10 MPa and a material b having an elastic modulus at 260° C. of 0.10 MPa or more.
• Layer B includes material a having an elastic modulus of less than 0.10 MPa at 260° C.
• Material a may be a low molecular weight compound or a high molecular weight compound, so long as it has an elastic modulus of less than 0.10 MPa at 260° C.
• the material a may be one type or two or more types.
• the elastic modulus of material a at 260° C. is preferably 0.05 MPa or less.
• the lower limit of the elastic modulus of material a at 260° C. is not particularly limited, and may be, for example, 0.1 kPa.
• the elastic modulus of material a at 260° C. is less than 0.10 MPa, the material has excellent step conformability.
• the elastic modulus of material a at 260° C. is measured by the following method.
• a film cross-section sample was prepared by obliquely cutting with a microtome so that the cross-section had a thickness of 50 ⁇ m.
• the 260°C elastic modulus of the portion of material a is measured as the indentation elastic modulus using a nanoindentation method.
• the indentation elastic modulus is measured by applying a load with a Vickers indenter at a loading rate of 0.28 mN/sec using a microhardness tester (for example, product name "DUH-W201" manufactured by Shimadzu Corporation), holding the maximum load of 10 mN for 10 seconds, and then unloading at a loading rate of 0.28 mN/sec.
• a microhardness tester for example, product name "DUH-W201" manufactured by Shimadzu Corporation
• material a is preferably a thermoplastic resin, a thermoplastic elastomer, an uncured or semi-cured thermosetting resin, or an uncured or semi-cured thermosetting elastomer.
• thermoplastic resins include polyurethane resins, polyester resins, (meth)acrylic resins, polystyrene resins, fluororesins, polyimide resins, fluorinated polyimide resins, polyamide resins, polyamideimide resins, polyetherimide resins, cellulose acylate resins, polyurethane resins, polyether ether ketone resins, polycarbonate resins, polyolefin resins (e.g., polyethylene resins, polypropylene resins, resins made of cyclic olefin copolymers, alicyclic polyolefin resins), polyarylate resins, polyethersulfone resins, polysulfone resins, fluorene ring-modified polycarbonate resins, alicyclic modified polycarbonate resins, fluorene ring-modified polyester resins, etc.
• polyolefin resins e.g., polyethylene resins, polypropylene resins, resins made
• thermoplastic elastomers examples include elastomers containing structural units derived from styrene (polystyrene-based elastomers), polyester-based elastomers, polyolefin-based elastomers, polyurethane-based elastomers, polyamide-based elastomers, polyacrylic-based elastomers, silicone-based elastomers, polyimide-based elastomers, etc.
• the thermoplastic elastomer may be a hydrogenated product.
• Polystyrene-based elastomers include styrene-butadiene-styrene block copolymers (SBS), styrene-isoprene-styrene block copolymers (SIS), polystyrene-poly(ethylene-propylene) diblock copolymers (SEP), polystyrene-poly(ethylene-propylene)-polystyrene triblock copolymers (SEPS), styrene-ethylene-butylene-styrene block copolymers (SEBS), polystyrene-poly(ethylene/ethylene-propylene)-polystyrene triblock copolymers (SEEPS), styrene-isobutylene-styrene block copolymers (SIBS), and hydrogenated versions of these.
• SBS styrene-butadiene-styrene block copolymers
• SIS
• material a is preferably a thermoplastic elastomer, more preferably an elastomer containing a structural unit derived from styrene, and even more preferably at least one selected from the group consisting of styrene-ethylene-butylene-styrene block copolymer, styrene-isobutylene-styrene block copolymer, styrene-ethylene-propylene-styrene copolymer, styrene-isoprene-styrene block copolymer, and hydrogenated products thereof.
• the content of material a is preferably 40% by mass to 95% by mass, and more preferably 60% by mass to 90% by mass, relative to the total mass of layer B.
• the weight average molecular weight of material a is preferably 1,000 or more, more preferably 10,000 or more, and even more preferably 30,000 or more.
• the upper limit of the weight average molecular weight is, for example, 1,000,000.
• the material a is preferably used as a powder in the production of the polymer film. More preferably, the method of converting the material a into a powder includes a swelling step of swelling the material a with a liquid medium, and a grinding step of grinding the swollen material A.
• Layer B contains material b having an elastic modulus of 0.10 MPa or more at 260° C.
• Material b may be a low molecular weight compound or a high molecular weight compound as long as it has an elastic modulus of 0.10 MPa or more at 260° C.
• the material b may be one type or two or more types.
• the elastic modulus of material b at 260° C. is preferably 1.0 MPa or more.
• the upper limit of the elastic modulus of material b at 260° C. is not particularly limited, and is, for example, 1000 MPa.
• the elastic modulus of material b at 260° C. is 0.10 MPa or more, the material has excellent heat resistance.
• the elastic modulus of material b at 260° C. is measured by the following method.
• a film cross-section sample was prepared by obliquely cutting with a microtome so that the cross-section had a thickness of 50 ⁇ m.
• the 260°C elastic modulus of the portion of material b is measured as the indentation elastic modulus using a nanoindentation method.
• the indentation elastic modulus is measured by applying a load with a Vickers indenter at a loading rate of 0.28 mN/sec using a microhardness tester (for example, product name "DUH-W201" manufactured by Shimadzu Corporation), holding the maximum load of 10 mN for 10 seconds, and then unloading at a loading rate of 0.28 mN/sec.
• a microhardness tester for example, product name "DUH-W201" manufactured by Shimadzu Corporation
• Examples of material b include liquid crystal polymers, fluororesins, polymers of compounds having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond, polyphenylene ether and its modified products, aromatic polyether ketone, phenolic resins, epoxy resins, polyimides, cyanate resins, bismaleimide resins, triazine resins, and other thermosetting resins.
• material b contains a liquid crystal polymer.
• the type of liquid crystal polymer is not particularly limited, and any known liquid crystal polymer can be used.
• the liquid crystal polymer may be a thermotropic liquid crystal polymer that exhibits liquid crystallinity in a molten state, or a lyotropic liquid crystal polymer that exhibits liquid crystallinity in a solution state. In the case of a thermotropic liquid crystal, it is preferable that the liquid crystal polymer melts at a temperature of 450° C. or less.
• liquid crystal polymers examples include liquid crystal polyester, liquid crystal polyester amide in which an amide bond has been introduced into liquid crystal polyester, liquid crystal polyester ether in which an ether bond has been introduced into liquid crystal polyester, and liquid crystal polyester carbonate in which a carbonate bond has been introduced into liquid crystal polyester.
• the liquid crystal polymer is preferably a polymer having an aromatic ring, and is more preferably an aromatic polyester or an aromatic polyester amide.
• the liquid crystal polymer may be a polymer in which an isocyanate-derived bond such as an imide bond, a carbodiimide bond, or an isocyanurate bond has been introduced into an aromatic polyester or an aromatic polyester amide.
• an isocyanate-derived bond such as an imide bond, a carbodiimide bond, or an isocyanurate bond has been introduced into an aromatic polyester or an aromatic polyester amide.
• liquid crystal polymer is preferably a fully aromatic liquid crystal polymer made using only aromatic compounds as raw material monomers.
• liquid crystal polymer examples include the following liquid crystal polymers. 1) A compound obtained by polycondensation of (i) an aromatic hydroxycarboxylic acid, (ii) an aromatic dicarboxylic acid, and (iii) at least one compound selected from the group consisting of an aromatic diol, an aromatic hydroxyamine, and an aromatic diamine. 2) Those obtained by polycondensation of multiple types of aromatic hydroxycarboxylic acids. 3) (i) a polycondensation product of an aromatic dicarboxylic acid and (ii) at least one compound selected from the group consisting of an aromatic diol, an aromatic hydroxyamine and an aromatic diamine.
• Polyester such as polyethylene terephthalate
• aromatic hydroxycarboxylic acid are polycondensed.
• the aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol, aromatic hydroxyamine and aromatic diamine may each independently be replaced with a derivative capable of undergoing polycondensation.
• the melting point of the liquid crystal polymer is preferably greater than 260°C, more preferably greater than 260°C and less than 350°C, and even more preferably greater than 260°C and less than 330°C.
• the melting point is measured using a differential scanning calorimeter.
• a differential scanning calorimeter For example, it is measured using a product called "DSC-60A Plus" (manufactured by Shimadzu Corporation).
• the heating rate in the measurement is 10°C/min.
• the weight average molecular weight of the liquid crystal polymer is preferably 1,000,000 or less, more preferably 3,000 to 300,000, even more preferably 5,000 to 100,000, and particularly preferably 5,000 to 30,000.
• the liquid crystal polymer preferably contains an aromatic polyesteramide from the viewpoint of further reducing the dielectric tangent.
• An aromatic polyesteramide is a resin having at least one aromatic ring and having an ester bond and an amide bond.
• the aromatic polyesteramide is preferably a fully aromatic polyesteramide.
• the aromatic polyester amide is preferably a crystalline polymer.
• the material B preferably contains a crystalline aromatic polyester amide.
• the dielectric loss tangent is further reduced.
• crystalline polymer refers to a polymer that has a clear endothermic peak, not a stepwise change in endothermic amount, in differential scanning calorimetry (DSC). Specifically, for example, it means that the half-width of the endothermic peak is within 10° C. when measured at a heating rate of 10° C./min. Polymers with a half-width exceeding 10° C. and polymers without a clear endothermic peak are classified as amorphous polymers and are distinguished from crystalline polymers.
• the aromatic polyester amide preferably contains a constitutional unit represented by the following formula 1, a constitutional unit represented by the following formula 2, and a constitutional unit represented by the following formula 3. -O-Ar 1 -CO- ... Formula 1 -CO-Ar 2 -CO-...Formula 2 —NH—Ar 3 —O— Formula 3
• Ar 1 , Ar 2 and Ar 3 each independently represent a phenylene group, a naphthylene group or a biphenylylene group.
• the structural unit represented by formula 1 will also be referred to as "unit 1", etc.
• the unit 1 can be introduced, for example, by using an aromatic hydroxycarboxylic acid as a raw material.
• the unit 2 can be introduced, for example, by using an aromatic dicarboxylic acid as a raw material.
• Unit 3 can be introduced, for example, by using an aromatic hydroxylamine as a raw material.
• aromatic hydroxycarboxylic acid, aromatic dicarboxylic acid, aromatic diol, and aromatic hydroxylamine may each be independently replaced with a derivative capable of polycondensation.
• aromatic hydroxycarboxylic acids and aromatic dicarboxylic acids can be replaced with aromatic hydroxycarboxylic acid esters and aromatic dicarboxylic acid esters by converting the carboxy group to an alkoxycarbonyl group or an aryloxycarbonyl group.
• Aromatic hydroxycarboxylic acids and aromatic dicarboxylic acids can be replaced with aromatic hydroxycarboxylic acid halides and aromatic dicarboxylic acid halides by converting the carboxy groups to haloformyl groups.
• Aromatic hydroxycarboxylic acids and aromatic dicarboxylic acids can be replaced with aromatic hydroxycarboxylic acid anhydrides and aromatic dicarboxylic acid anhydrides by converting the carboxy groups to acyloxycarbonyl groups.
• polycondensable derivatives of compounds having a hydroxy group such as aromatic hydroxycarboxylic acids and aromatic hydroxyamines
• examples of polycondensable derivatives of compounds having a hydroxy group include those obtained by acylation of a hydroxy group into an acyloxy group (acylated products).
• aromatic hydroxycarboxylic acids and aromatic hydroxylamines can be replaced with their acylated counterparts by acylation of the hydroxy group to convert it to an acyloxy group.
• polycondensable derivatives of aromatic hydroxylamines include those obtained by acylation of the amino group to an acylamino group (acylated product).
• aromatic hydroxyamines can be replaced with acylated products by acylation of the amino group to convert them to acylamino groups.
• Ar 1 is preferably a p-phenylene group, a 2,6-naphthylene group, or a 4,4'-biphenylylene group, and more preferably a 2,6-naphthylene group.
• unit 1 is, for example, a constitutional unit derived from p-hydroxybenzoic acid.
• unit 1 is, for example, a constitutional unit derived from 6-hydroxy-2-naphthoic acid.
• Ar 1 is a 4,4'-biphenylylene group
• unit 1 is, for example, a constitutional unit derived from 4'-hydroxy-4-biphenylcarboxylic acid.
• Ar 2 is preferably a p-phenylene group, an m-phenylene group, or a 2,6-naphthylene group, and more preferably an m-phenylene group.
• unit 2 is, for example, a constitutional unit derived from terephthalic acid.
• unit 2 is, for example, a constitutional unit derived from isophthalic acid.
• Ar 2 is a 2,6-naphthylene group
• unit 2 is, for example, a constitutional unit derived from 2,6-naphthalenedicarboxylic acid.
• Ar 3 is preferably a p-phenylene group or a 4,4′-biphenylylene group, and more preferably a p-phenylene group.
• unit 3 is, for example, a constitutional unit derived from p-aminophenol.
• unit 3 is, for example, a constitutional unit derived from 4-amino-4'-hydroxybiphenyl.
• the content of units 1 is preferably 30 mol % or more, the content of units 2 is preferably 35 mol % or less, and the content of units 3 is preferably 35 mol % or less.
• the content of unit 1 is more preferably 30 mol % to 80 mol %, further preferably 30 mol % to 60 mol %, and particularly preferably 30 mol % to 40 mol %, based on the total content of unit 1, unit 2, and unit 3.
• the content of unit 2 is preferably 10 mol % to 35 mol %, more preferably 20 mol % to 35 mol %, and particularly preferably 30 mol % to 35 mol %, based on the total content of unit 1, unit 2, and unit 3.
• the content of unit 3 is preferably 10 mol % to 35 mol %, more preferably 20 mol % to 35 mol %, and particularly preferably 30 mol % to 35 mol %, based on the total content of unit 1, unit 2, and unit 3.
• the total content of each structural unit is the sum of the amounts (moles) of each structural unit, which is calculated by dividing the mass of each structural unit constituting the aromatic polyesteramide by the formula weight of the structural unit.
• the ratio of the content of unit 2 to the content of unit 3, expressed as [content of unit 2]/[content of unit 3] (mol/mol), is preferably 0.9/1 to 1/0.9, more preferably 0.95/1 to 1/0.95, and even more preferably 0.98/1 to 1/0.98.
• the aromatic polyesteramide may have two or more types of units 1 to 3, each of which is independent.
• the aromatic polyesteramide may also have other structural units in addition to units 1 to 3.
• the content of the other structural units is preferably 10 mol % or less, more preferably 5 mol % or less, based on the total content of all structural units.
• Aromatic polyesteramides are preferably produced by melt polymerizing raw material monomers that correspond to the structural units that make up the aromatic polyesteramide.
• the weight average molecular weight of the aromatic polyester amide is preferably 1,000,000 or less, more preferably 3,000 to 300,000, even more preferably 5,000 to 100,000, and particularly preferably 5,000 to 30,000.
• -Fluorine resin- Material b may be a fluororesin from the viewpoints of heat resistance and mechanical strength.
• the type of fluororesin is not particularly limited, and any known fluororesin can be used.
• Fluororesins include homopolymers and copolymers that contain structural units derived from fluorinated ⁇ -olefin monomers, i.e., ⁇ -olefin monomers that contain at least one fluorine atom. Fluororesins also include copolymers that contain structural units derived from fluorinated ⁇ -olefin monomers and structural units derived from non-fluorinated ethylenically unsaturated monomers that are reactive with fluorinated ⁇ -olefin monomers.
• Fluorinated ⁇ -olefin monomers include CF 2 ⁇ CF 2 , CHF ⁇ CF 2 , CH 2 ⁇ CF 2 , CHCl ⁇ CHF, CCIF ⁇ CF 2 , CCl 2 ⁇ CF 2 , CCIF ⁇ CCIF, CHF ⁇ CCl 2 , CH 2 ⁇ CCIF , CCl 2 ⁇ CCIF, CF 3 CF ⁇ CF 2 , CF 3 CF ⁇ CHF , CF 3 CH ⁇ CF 2 , CF 3 CH ⁇ CH 2 , CHF 2 CH ⁇ CHF, CF 3 CF ⁇ CF 2 , and perfluoro ( alkyl having 2 to 8 carbon atoms)vinyl ethers (e.g., perfluoromethyl vinyl ether, perfluoropropyl vinyl ether, and perfluorooctyl vinyl ether).
• perfluoro ( alkyl having 2 to 8 carbon atoms)vinyl ethers e.g., perfluoromethyl vinyl ether
• the fluorinated ⁇ -olefin monomer is preferably at least one monomer selected from the group consisting of tetrafluoroethylene (CF 2 ⁇ CF 2 ), chlorotrifluoroethylene (CCIF ⁇ CF 2 ), (perfluorobutyl)ethylene, vinylidene fluoride (CH 2 ⁇ CF 2 ), and hexafluoropropylene (CF 2 ⁇ CFCF 3 ).
• Non-fluorinated ethylenically unsaturated monomers include ethylene, propylene, butene, ethylenically unsaturated aromatic monomers (eg, styrene and ⁇ -methylstyrene), and the like.
• the fluorinated ⁇ -olefin monomers may be used alone or in combination of two or more kinds.
• the non-fluorinated ethylenically unsaturated monomers may be used alone or in combination of two or more kinds.
• fluororesins include polychlorotrifluoroethylene (PCTFE), poly(chlorotrifluoroethylene-propylene), poly(ethylene-tetrafluoroethylene) (ETFE), poly(ethylene-chlorotrifluoroethylene) (ECTFE), poly(hexafluoropropylene), poly(tetrafluoroethylene) (PTFE), poly(tetrafluoroethylene-ethylene-propylene), poly(tetrafluoroethylene-hexafluoropropylene) (FEP), poly(tetrafluoroethylene-propylene) (FEPM), poly(tetrafluoroethylene-perfluoropropylene vinyl ether), poly(tetrafluoroethylene-perfluoroalkyl vinyl ether) (PFA) (e.g., poly(tetrafluoroethylene-perfluoropropyl vinyl ether)), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), poly((
• the fluororesin may have structural units derived from fluorinated ethylene or fluorinated propylene.
• the fluororesin may be used alone or in combination of two or more kinds.
• the fluororesin is preferably FEP, PFA, ETFE, or PTFE.
• FEP is available from DuPont under the trade name TEFLON FEP, or from Daikin Industries, Ltd. under the trade name NEOFLON FEP.
• PFA is available from Daikin Industries, Ltd. under the trade name NEOFLON PFA, from DuPont under the trade name TEFLON PFA, or from Solvay Solexis under the trade name HYFLON PFA.
• the fluororesin contains PTFE.
• the PTFE may be a PTFE homopolymer, a partially modified PTFE homopolymer, or a combination containing one or both of these.
• the partially modified PTFE homopolymer preferably contains less than 1% by mass of structural units derived from comonomers other than tetrafluoroethylene, based on the total mass of the polymer.
• the fluororesin may be a crosslinkable fluoropolymer having a crosslinkable group.
• the crosslinkable fluoropolymer can be crosslinked by a conventionally known crosslinking method.
• One representative crosslinkable fluoropolymer is a fluoropolymer having (meth)acryloyloxy.
• R is an oligomer chain containing constitutional units derived from a fluorinated ⁇ -olefin monomer
• R′ is H or —CH3
• n is 1 to 4.
• R may also be a fluorine-based oligomer chain containing constitutional units derived from tetrafluoroethylene.
• a crosslinked fluoropolymer network can be formed by exposing a fluoropolymer having (meth)acryloyloxy groups to a free radical source to initiate a radical crosslinking reaction via the (meth)acryloyloxy groups on the fluororesin.
• the free radical source is not particularly limited, but suitable examples include a photoradical polymerization initiator or an organic peroxide. Suitable photoradical polymerization initiators and organic peroxides are well known in the art.
• Crosslinkable fluoropolymers are commercially available, such as Viton B manufactured by DuPont.
• the material b may be a polymer of a compound having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond.
• polymers of compounds having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond include thermoplastic resins having structural units derived from cyclic olefin monomers such as norbornene or polycyclic norbornene monomers.
• the polymer of a compound having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond may be a ring-opening polymer of the above-mentioned cyclic olefin or a hydrogenated product of a ring-opening copolymer using two or more kinds of cyclic olefins, or may be an addition polymer of a cyclic olefin and an aromatic compound having an ethylenically unsaturated bond such as a chain olefin or a vinyl group.
• a polar group may be introduced into the polymer of a compound having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond.
• the polymer of the compound having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond may be used alone or in combination of two or more types.
• the ring structure of the cyclic aliphatic hydrocarbon group may be a monocyclic ring, a condensed ring in which two or more rings are condensed, or a bridged ring.
• Examples of the ring structure of the cyclic aliphatic hydrocarbon group include a cyclopentane ring, a cyclohexane ring, a cyclooctane ring, an isophorone ring, a norbornane ring, and a dicyclopentane ring.
• the compound having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond is not particularly limited, and may be a (meth)acrylate compound having a cyclic aliphatic hydrocarbon group, a (meth)acrylamide compound having a cyclic aliphatic hydrocarbon group, or a vinyl compound having a cyclic aliphatic hydrocarbon group. Among them, a (meth)acrylate compound having a cyclic aliphatic hydrocarbon group is preferred.
• the compound having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond may be a monofunctional ethylenically unsaturated compound or a polyfunctional ethylenically unsaturated compound.
• the number of cycloaliphatic hydrocarbon groups in the compound having a cycloaliphatic hydrocarbon group and a group having an ethylenically unsaturated bond may be one or more, and may be two or more.
• the polymer of a compound having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond may be a polymer obtained by polymerizing a compound having at least one type of cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond, and may be a polymer of a compound having two or more types of cyclic aliphatic hydrocarbon groups and a group having an ethylenically unsaturated bond, or may be a copolymer with another ethylenically unsaturated compound that does not have a cyclic aliphatic hydrocarbon group.
• the polymer of a compound having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond is preferably a cycloolefin polymer.
• Polyphenylene ether- Material b may be polyphenylene ether.
• the polyphenylene ether preferably has an average number of phenolic hydroxyl groups at the molecular terminals (number of terminal hydroxyl groups) per molecule, from the viewpoints of dielectric tangent and heat resistance, of 1 to 5, and more preferably 1.5 to 3.
• the number of terminal hydroxyl groups of polyphenylene ether can be known from, for example, the specification value of the polyphenylene ether product.
• the number of terminal hydroxyl groups is expressed, for example, as the average number of phenolic hydroxyl groups per molecule of all polyphenylene ethers present in 1 mole of polyphenylene ether.
• the polyphenylene ether may be used alone or in combination of two or more kinds.
• polyphenylene ethers examples include polyphenylene ethers made of 2,6-dimethylphenol and at least one of a difunctional phenol and a trifunctional phenol, and poly(2,6-dimethyl-1,4-phenylene oxide). More specifically, the polyphenylene ether is preferably a compound having a structure represented by the formula (PPE).
• X represents an alkylene group having 1 to 3 carbon atoms or a single bond
• m represents an integer of 0 to 20
• n represents an integer of 0 to 20
• the sum of m and n represents an integer of 1 to 30.
• the alkylene group for X may, for example, be a dimethylmethylene group.
• the weight average molecular weight (Mw) is preferably 500 to 5,000, and more preferably 500 to 3,000, from the viewpoints of heat resistance and film formability. If the polyphenylene ether is not thermally cured, the weight average molecular weight (Mw) is not particularly limited, but is preferably 3,000 to 100,000, and more preferably 5,000 to 50,000.
• Aromatic polyether ketone - Material b may be an aromatic polyether ketone.
• the aromatic polyether ketone is not particularly limited, and any known aromatic polyether ketone can be used.
• the aromatic polyether ketone is preferably polyether ether ketone.
• Polyetheretherketone is a type of aromatic polyetherketone, and is a polymer in which bonds are arranged in the following order: ether bond, ether bond, and carbonyl bond. Each bond is preferably linked by a divalent aromatic group.
• the aromatic polyether ketones may be used alone or in combination of two or more kinds.
• aromatic polyetherketones examples include polyetheretherketone (PEEK) having a chemical structure represented by the following formula (P1), polyetherketone (PEK) having a chemical structure represented by the following formula (P2), polyetherketoneketone (PEKK) having a chemical structure represented by the following formula (P3), polyetheretherketoneketone (PEEKK) having a chemical structure represented by the following formula (P4), and polyetherketoneetherketoneketone (PEKEKK) having a chemical structure represented by the following formula (P5).
• n in each of formulas (P1) to (P5) is preferably 10 or more, and more preferably 20 or more.
• n is preferably 5,000 or less, and more preferably 1,000 or less. In other words, n is preferably 10 to 5,000, and more preferably 20 to 1,000.
• material b is preferably at least one selected from the group consisting of liquid crystal polymers, polymers of compounds having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond, and fluororesins, and is more preferably an aromatic polyesteramide.
• material b may be in a particulate form.
• material b may be organic particles or inorganic particles.
• layer B contains particulate material b, it is preferable that layer B also contains non-particulate material b.
• resins constituting the organic particles include polyethylene, polystyrene, urea-formaldehyde filler, polyester, cellulose, acrylic resin, fluororesin, cured epoxy resin, crosslinked benzoguanamine resin, crosslinked acrylic resin, and liquid crystal polymer.
• the resins constituting the organic particles may be one type or two or more types.
• the organic particles may also be fibrous, such as nanofibers, or hollow resin particles.
• the organic particles are preferably fluororesin particles, polyester resin particles, polyethylene particles, liquid crystal polymer particles, or nanofibers of cellulose resin, more preferably polytetrafluoroethylene particles, polyethylene particles, or liquid crystal polymer particles, and particularly preferably liquid crystal polymer particles.
• the liquid crystal polymer particles refer to, but are not limited to, a powdered liquid crystal obtained by polymerizing a liquid crystal polymer and pulverizing it with a pulverizer or the like.
• the preferred embodiments of the liquid crystal polymer constituting the liquid crystal polymer particles are the same as those of the liquid crystal polymer described above.
• Examples of compounds constituting the inorganic particles include boron nitride ( BN ), Al2O3 , AlN, TiO2 , SiO2 , barium titanate, strontium titanate, aluminum hydroxide, and calcium carbonate.
• the compounds constituting the inorganic particles may be one type or two or more types.
• metal oxide particles or fibers are preferred as inorganic particles, silica particles, titania particles, or glass fibers are more preferred, and silica particles or glass fibers are particularly preferred.
• the average particle size of the inorganic particles is preferably 5 nm to 20 ⁇ m, more preferably 10 nm to 10 ⁇ m, even more preferably 20 nm to 1 ⁇ m, and particularly preferably 25 nm to 500 nm.
• the layer B may contain other additives in addition to the material a and the material b.
• known additives can be used, such as a curing agent, a leveling agent, a defoaming agent, an antioxidant, an ultraviolet absorbing agent, a flame retardant, and a colorant.
• Layer B may also contain a foaming agent that disappears when heated or that decomposes when heated to release a gas.
• the foaming agent may be an organic foaming agent or an inorganic foaming agent.
• organic foaming agents examples include particles containing acrylic resin as a main component, particles containing ethyl cellulose resin as a main component, particles containing butyral resin as a main component, nitrosamine compounds such as dinitrosopentamethylenetetramine (DPT), azo compounds such as azodicarbonamide (ADCA), and hydrazine compounds such as 4,4'-oxybisbenzenesulfonylhydrazide (OBSH) and hydrazodicarbonamide (HDCA).
• DPT dinitrosopentamethylenetetramine
• ADCA azo compounds
• hydrazine compounds such as 4,4'-oxybisbenzenesulfonylhydrazide (OBSH) and hydrazodicarbonamide (HDCA).
• inorganic foaming agents examples include bicarbonates such as sodium bicarbonate; carbonates; and combinations of bicarbonates and organic acid salts such as sodium citrate.
• the elastic modulus of Layer B at 25° C. is 500 MPa or less, and preferably 300 MPa or less. When the elastic modulus of Layer B at 25° C. is 500 MPa or less, the peel strength against the metal layer or metal wiring is improved.
• the lower limit of the elastic modulus of Layer B at 25° C. is not particularly limited, but may be 10 MPa from the viewpoint of handling properties.
• Layer B has an elastic modulus of 0.60 MPa or less at 160°C, and preferably 0.50 MPa or less. When layer B has an elastic modulus of 0.60 MPa or less at 160°C, it has excellent step conformability. There is no particular limit to the lower limit of the elastic modulus of layer B at 160°C, but from the viewpoint of processability, it may be 0.1 kPa.
• the elastic modulus of Layer B at 25° C. and 160° C. is measured by the following method.
• a film cross-section sample was prepared by obliquely cutting with a microtome so that the cross-section had a thickness of 50 ⁇ m.
• the elastic modulus of layer B is measured as the indentation elastic modulus using a nanoindentation method.
• the indentation elastic modulus is measured by applying a load at a loading rate of 0.28 mN/sec with a Vickers indenter using a microhardness tester (e.g., product name "DUH-W201" manufactured by Shimadzu Corporation), holding the maximum load of 10 mN for 10 seconds, and then unloading at a loading rate of 0.28 mN/sec.
• the cross-sectional sample is measured at 20 arbitrary positions at 25°C and 160°C, and the average value is taken as the elastic modulus.
• the average thickness of layer B is preferably 5 ⁇ m to 50 ⁇ m, more preferably 10 ⁇ m to 40 ⁇ m, and even more preferably 15 ⁇ m to 30 ⁇ m.
• the polymer film according to the present disclosure has a layer A on which the above-mentioned layer B is provided.
• the layer A preferably contains a polymer having a dielectric loss tangent of 0.01 or less.
• Layer A may contain only one type of polymer with a dielectric tangent of 0.01 or less, or may contain two or more types.
• the dielectric tangent of a polymer having a dielectric tangent of 0.01 or less is preferably 0.005 or less, and more preferably greater than 0 and less than 0.003, from the viewpoint of the dielectric tangent of the polymer film.
• polymers with a dielectric tangent of 0.01 or less include liquid crystal polymers, fluororesins, polymers of compounds having a cyclic aliphatic hydrocarbon group and a group having an ethylenically unsaturated bond, thermoplastic resins such as polyether ether ketone, polyolefin, polyamide, polyester, polyphenylene sulfide, polyether ketone, polycarbonate, polyether sulfone, polyphenylene ether and modified products thereof, and polyether imide; elastomers such as copolymers of glycidyl methacrylate and polyethylene; and thermosetting resins such as phenol resins, epoxy resins, polyimides, and cyanate resins.
• thermoplastic resins such as polyether ether ketone, polyolefin, polyamide, polyester, polyphenylene sulfide, polyether ketone, polycarbonate, polyether sulfone, polyphenylene ether and modified products thereof, and polyether
• the polymer having a dielectric tangent of 0.01 or less is preferably a liquid crystal polymer. That is, it is preferable that layer A contains a liquid crystal polymer.
• the preferred embodiment of the liquid crystal polymer is the same as the preferred embodiment of the liquid crystal polymer that may be contained in layer B described above.
• Layer A may contain a filler in addition to the polymer having a dielectric tangent of 0.01 or less.
• the filler may be particulate or fibrous, and may be inorganic or organic particles. Specific examples of inorganic and organic particles are as described above.
• layer A contains particles with a melting point of 300°C or higher.
• layer A contains particles having a melting point of 300° C. or higher, the heat resistance is improved.
• the particles having a melting point of 300° C. or more preferably have a melting point of 1000° C. or more.
• the upper limit of the melting point is, for example, 3000° C.
• inorganic particles having a melting point of 300° C. or higher include boron nitride (BN), aluminum oxide (Al 2 O 3 ), aluminum nitride (AlN), titanium dioxide (TiO 2 ), silicon dioxide (SiO 2 ), barium titanate, strontium titanate, aluminum hydroxide, calcium carbonate, and materials containing two or more of these.
• organic particles having a melting point of 300° C. or higher include liquid crystal polymer particles and PTFE particles.
• the average particle size of particles having a melting point of 300°C or more is preferably 4.0 ⁇ m or less, more preferably 2.0 ⁇ m or less, and even more preferably 1.0 ⁇ m or less, from the viewpoint of making the surface roughness Rc of the side of layer A on which layer B is disposed 5 ⁇ m or less.
• the lower limit of the average particle size of particles having a melting point of 300°C or more is not particularly limited, and may be, for example, 0.05 ⁇ m.
• the average particle size of the particles contained in layer A and having a melting point of 300° C. or higher is measured by the following method. First, the surface of a polymer film is cut with a microtome to prepare a film cross-section sample. The cross-section is observed with a scanning electron microscope (SEM) at 10,000 times magnification in 100 fields of view. 100 particles are selected at random. The lengths of the selected particles in the major axis direction are measured, and the average value is used.
• SEM scanning electron microscope
• Layer A may contain only one type of filler, or may contain two or more types of fillers.
• the content of the filler is preferably 30% by mass to 95% by mass, more preferably 50% by mass to 90% by mass, and particularly preferably 60% by mass to 80% by mass, relative to the total mass of Layer A, from the viewpoints of the dielectric tangent, heat resistance, and step-following ability of the laminate.
• Layer A may contain additives other than the above-mentioned components. Preferred embodiments of the other additives that may be contained in Layer A are the same as preferred embodiments of the other additives that may be contained in Layer B.
• the layer A may contain, as other additives, resins other than the polymer having a dielectric loss tangent of 0.01 or less.
• resins other than polymers having a dielectric tangent of 0.01 or less include thermoplastic resins other than liquid crystal polyesters, such as polypropylene, polyamide, polyesters other than liquid crystal polyesters, polyphenylene sulfide, polyether ketone, polycarbonate, polyether sulfone, polyphenylene ether and modified products thereof, and polyether imide; elastomers such as copolymers of glycidyl methacrylate and polyethylene; and thermosetting resins such as phenol resins, epoxy resins, polyimide resins, and cyanate resins.
• the total content of other additives in Layer A is preferably 25 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of the polymer having a dielectric tangent of 0.01 or less.
• the elastic modulus of the layer A at 160° C. is preferably more than 0.60 MPa, and more preferably 10 MPa or more.
• the layer A can support the layer B and has excellent step conformability.
• the upper limit of the elastic modulus of the layer A at 160° C. is not particularly limited, but may be 1000 MPa from the viewpoint of processability.
• the elastic modulus of Layer A at 160° C. is measured by the following method.
• a film cross-section sample was prepared by obliquely cutting with a microtome so that the cross-section had a thickness of 50 ⁇ m.
• the elastic modulus of layer A is measured as the indentation elastic modulus using a nanoindentation method.
• the indentation elastic modulus is measured by applying a load at a loading rate of 0.28 mN/sec with a Vickers indenter using a microhardness tester (for example, product name "DUH-W201" manufactured by Shimadzu Corporation), holding the maximum load of 10 mN for 10 seconds, and then unloading at a loading rate of 0.28 mN/sec.
• the cross-sectional sample is measured at 20 arbitrary positions at 160°C, and the average value is taken as the elastic modulus.
• the surface roughness Rc of layer A on the side where layer B is disposed is 5 ⁇ m or less, and preferably 3 ⁇ m or less.
• a surface roughness Rc of 5 ⁇ m or less provides excellent heat resistance.
• the surface roughness Rc is preferably 0.1 ⁇ m or more, and more preferably 1.0 ⁇ m or more.
• layer A When layer B is disposed on one side of layer A, layer A only needs to have a surface roughness Rc of 5 ⁇ m or less on the side on which layer B is disposed, and there is no particular limitation on the surface roughness Rc of the side opposite to the side on which layer B is disposed.
• layer A When layer B is disposed on both sides of layer A, layer A has a surface roughness Rc of 5 ⁇ m or less on both sides.
• the surface roughness Rc is measured by the following method.
• a cross section is obtained by obliquely cutting the laminate of Layer A and Layer B with a microtome.
• the average height Rc of the interface of Layer A on the Layer B side is measured in accordance with JIS B0601 2001.
• the evaluation length is 500 ⁇ m.
• a method for making the surface roughness Rc of layer A 5 ⁇ m or less is to mix small particles into layer A.
• a dispersion process e.g., bead mill process
• a disperser By carrying out the bead mill process, the disintegration and pulverization of particle agglomerates are promoted, the particle size becomes smaller, and the surface roughness Rc can be reduced.
• the average thickness of layer A is not particularly limited, but from the viewpoint of the dielectric tangent, heat resistance, and suppression of wiring distortion of the laminate, it is preferably 5 ⁇ m to 90 ⁇ m, more preferably 10 ⁇ m to 70 ⁇ m, and particularly preferably 15 ⁇ m to 50 ⁇ m.
• the polymer film according to the present disclosure preferably further comprises layer C in addition to layer A and layer B, and more preferably comprises layer B, layer A, and layer C in this order.
• Layer C is preferably an adhesive layer, i.e., Layer C is preferably a surface layer (outermost layer).
• layer C contains at least one type of polymer.
• the preferred embodiment of the polymer used in layer C is the same as the preferred embodiment of the polymer used in layer A having a dielectric tangent of 0.01 or less.
• the polymer contained in layer C may be the same as or different from the polymer contained in layer A or layer B, but from the viewpoint of adhesion between layer A and layer C, it is preferable that the polymer is the same as the polymer contained in layer A.
• layer C contains an epoxy resin to bond the metal layer to layer A.
• the epoxy resin is preferably a crosslinked product of a multifunctional epoxy compound.
• a multifunctional epoxy compound is a compound having two or more epoxy groups.
• the number of epoxy groups in a multifunctional epoxy compound is preferably 2 to 4.
• layer C contains an aromatic polyester amide and an epoxy resin.
• the layer C may contain a filler.
• the preferred embodiments of the filler used in Layer C are the same as those of the filler used in Layer A.
• Layer C may contain additives other than those mentioned above. Preferred embodiments of the other additives used in Layer C are the same as those of the other additives used in Layer A, except as described below.
• the average thickness of layer C is preferably thinner than the average thickness of layer A from the viewpoints of the dielectric tangent of the laminate and adhesion to metals.
• T A /T C which is the ratio of the average thickness T A of Layer A to the average thickness T C of Layer C, is preferably greater than 1, more preferably from 2 to 100, even more preferably from 2.5 to 20, and particularly preferably from 3 to 10, from the viewpoints of the dielectric tangent of the laminate and the adhesion to the metal layer.
• T B /T C which is the ratio of the average thickness T B of Layer B to the average thickness T C of Layer C, is preferably greater than 1, more preferably from 2 to 100, even more preferably from 2.5 to 20, and particularly preferably from 3 to 10, from the viewpoints of the dielectric tangent of the laminate and the adhesion to the metal layer.
• the average thickness of layer C is preferably 0.1 ⁇ m to 20 ⁇ m, more preferably 0.5 ⁇ m to 15 ⁇ m, even more preferably 1 ⁇ m to 10 ⁇ m, and particularly preferably 2 ⁇ m to 8 ⁇ m.
• the method for measuring the average thickness of each layer in the polymer film according to the present disclosure is as follows.
• the polymer film is cut on a plane perpendicular to the surface of the polymer film, the thickness is measured at five or more points on the cross section, and the average of these measurements is taken as the average thickness.
• the polymer film according to the present disclosure has a dielectric loss tangent of 0.01 or less, preferably 0.005 or less, and more preferably greater than 0 and 0.003 or less.
• the dielectric loss tangent is measured by the following method.
• the dielectric loss tangent is measured by a resonance perturbation method at a frequency of 10 GHz.
• a 10 GHz cavity resonator (Kanto Electronics Application Development Co., Ltd.'s "CP531") is connected to a network analyzer (Agilent Technology's "E8363B”), a polymer film is inserted into the cavity resonator, and the dielectric loss tangent is measured from the change in resonance frequency before and after insertion for 96 hours under an environment of 25°C temperature and 60% RH.
• the average thickness of the polymer film according to the present disclosure is not particularly limited, but from the viewpoint of dielectric tangent and step conformability, it is preferably 5 ⁇ m to 90 ⁇ m, more preferably 10 ⁇ m to 70 ⁇ m, and particularly preferably 15 ⁇ m to 50 ⁇ m.
• the average thickness of the polymer film is measured at any five points using an adhesive film thickness meter, such as an electronic micrometer (product name "KG3001A", manufactured by Anritsu Corporation), and the average value is calculated.
• an adhesive film thickness meter such as an electronic micrometer (product name "KG3001A", manufactured by Anritsu Corporation)
• the method for producing the polymer film according to the present disclosure is not particularly limited, and known methods can be referred to.
• Suitable film-forming methods include, for example, co-casting, multi-layer coating, and co-extrusion. Among these, the co-casting method is preferred.
• a composition for forming layer A When manufacturing a multi-layer structure by co-casting or multi-layer coating, it is preferable to carry out the co-casting or multi-layer coating using a composition for forming layer A, a composition for forming layer B, a composition for forming layer C, etc., in which the components of each layer are dissolved or dispersed in a solvent.
• Solvents include, for example, halogenated hydrocarbons such as dichloromethane, chloroform, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, 1-chlorobutane, chlorobenzene, and o-dichlorobenzene; halogenated phenols such as p-chlorophenol, pentachlorophenol, and pentafluorophenol; ethers such as diethyl ether, tetrahydrofuran, and 1,4-dioxane; ketones such as acetone and cyclohexanone; esters such as ethyl acetate and ⁇ -butyrolactone; and ethylene carbonate.
• halogenated hydrocarbons such as dichloromethane, chloroform, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, 1-
• organic solvent examples include carbonates such as propylene carbonate and propylene carbonate; amines such as triethylamine; nitrogen-containing heterocyclic aromatic compounds such as pyridine; nitriles such as acetonitrile and succinonitrile; amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone, and urea compounds such as tetramethylurea; nitro compounds such as nitromethane and nitrobenzene; sulfur compounds such as dimethyl sulfoxide and sulfolane; and phosphorus compounds such as hexamethylphosphoramide and tri-n-butylphosphoric acid, and two or more of these may be used.
• carbonates such as propylene carbonate and propylene carbonate
• amines such as triethylamine
• nitrogen-containing heterocyclic aromatic compounds such as pyridine
• nitriles such as acetonitrile and succinon
• the solvent is preferably a solvent mainly composed of an aprotic compound, particularly an aprotic compound without halogen atoms, because it is less corrosive and easier to handle, and the proportion of the aprotic compound in the entire solvent is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, and particularly preferably 90% by mass to 100% by mass.
• amides such as N,N-dimethylformamide, N,N-dimethylacetamide, tetramethylurea, and N-methylpyrrolidone, or esters such as ⁇ -butyrolactone, because they easily dissolve liquid crystal polymers, and N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone are more preferable.
• a solvent mainly composed of a compound having a dipole moment of 3 to 5 is preferred because it easily dissolves the liquid crystal polymer, and the proportion of the compound having a dipole moment of 3 to 5 in the entire solvent is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, and particularly preferably 90% by mass to 100% by mass.
• the aprotic compound it is preferable to use a compound having a dipole moment of 3 to 5.
• the solvent is preferably a solvent mainly composed of a compound having a boiling point of 220° C. or lower at 1 atmospheric pressure, because it is easy to remove.
• the proportion of the compound having a boiling point of 220° C. or lower at 1 atmospheric pressure in the entire solvent is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, and particularly preferably 90% by mass to 100% by mass.
• the aprotic compound it is preferable to use a compound having a boiling point of 220° C. or lower at 1 atmospheric pressure.
• a support may be used when the film is produced by the above-mentioned co-casting method, multi-layer coating method, co-extrusion method, or the like.
• the support examples include a metal drum, a metal band, a glass plate, a resin film, and a metal foil.
• the support is preferably a metal drum, a metal band, or a resin film.
• the support may have a surface treatment layer formed on its surface so that it can be easily peeled off.
• the surface treatment layer may be made of hard chrome plating, fluororesin, or the like.
• the average thickness of the support is not particularly limited, but is preferably from 25 ⁇ m to 75 ⁇ m, and more preferably from 50 ⁇ m to 75 ⁇ m.
• the method for producing a polymer film according to the present disclosure can be appropriately combined with stretching in terms of controlling molecular orientation and adjusting the thermal expansion coefficient and mechanical properties.
• the stretching method is not particularly limited, and known methods can be referred to. It may be performed in a state containing a solvent or in a dry film state. Stretching in a state containing a solvent may be performed by gripping and stretching the laminate, or may be performed by utilizing autogenous shrinkage due to drying without stretching. Stretching is particularly effective for the purpose of improving the breaking elongation and breaking strength when the film brittleness is reduced by the addition of inorganic fillers, etc.
• the polymer film according to the present disclosure can be used for various applications, and is particularly suitable for use as a film for electronic components such as printed wiring boards, and more particularly suitable for use as a flexible printed circuit board. Moreover, the polymer film according to the present disclosure can be suitably used as a liquid crystal polymer film for metal bonding.
• a laminate according to the present disclosure includes a polymer film according to the present disclosure and a metal layer or metal wiring disposed on at least one surface of the polymer film according to the present disclosure.
• the layer configuration of the laminate according to the present disclosure may be in the following form.
• Aspect 1 Metal Layer/Polymer Film (Layer A/Layer B)
• Aspect 2 Metal Layer/Polymer Film (Layer C/Layer A/Layer B)
• Aspect 3 Metal layer (also referred to as second metal layer)/polymer film (Layer A/Layer B)/metal layer
• Aspect 4 Metal layer (also referred to as second metal layer)/polymer film (Layer C/Layer A/Layer B)/metal layer
• the metal layer may be replaced with a metal wiring.
• the laminate according to the present disclosure preferably includes Layer B, Layer A, and a metal layer in this order. Specific examples include the above-mentioned aspects 1 and 2.
• the laminate according to the present disclosure preferably further includes a second metal layer, and includes the second metal layer, layer A, layer B, and a metal layer or metal wiring in this order.
• Specific examples include the above-mentioned aspects 3 and 4.
• the metal layer or metal wiring may be made of a conventionally known material, and is preferably made of silver or copper, and more preferably made of copper.
• Metal layers or metal wiring may be disposed on both sides of the polymer film.
• the two metal layers or metal wiring may be metal layers or metal wiring of the same material, thickness and shape, or metal layers or metal wiring of different materials, thickness and shape. From the viewpoint of characteristic impedance adjustment, the two metal layers or metal wiring may be metal layers or metal wiring of different materials and thicknesses.
• the metal layer is a rolled metal foil formed by a rolling method, or an electrolytic metal foil formed by an electrolytic method.
• the metal layer or metal wiring is disposed on layer B of the polymer film, and the peel strength between layer B and the metal layer or metal wiring is preferably 0.3 kN/m or more, more preferably 0.5 kN/m or more, and even more preferably 0.5 kN/m or more.
• the upper limit of the peel strength is not particularly limited, but may be 5 kN/m from the viewpoint of processability.
• the peel strength between Layer B and a metal layer or metal wiring is measured by the following method.
• a peel test piece having a width of 1.0 cm is prepared from a laminate (laminate with metal) of a polymer film and a metal layer or metal wiring, and the peel test piece is fixed to a flat plate with double-sided adhesive tape.
• the strength (kN/m) is measured when the peel test piece is peeled at a rate of 50 mm/min by the 90° method in accordance with JIS C 5016 (1994).
• the average thickness of the metal layer is not particularly limited, but is preferably 2 ⁇ m to 20 ⁇ m, more preferably 3 ⁇ m to 18 ⁇ m, and even more preferably 5 ⁇ m to 12 ⁇ m.
• the copper foil may be a carrier-attached copper foil that is formed releasably on a support (carrier).
• the carrier may be a known one.
• the average thickness of the carrier is not particularly limited, but is preferably 10 ⁇ m to 100 ⁇ m, and more preferably 18 ⁇ m to 50 ⁇ m.
• the metal layer may be a metal layer having a circuit pattern. It is also preferable to process the metal layer into a desired circuit pattern, for example, by etching, to form a flexible printed circuit board. There are no particular limitations on the etching method, and any known etching method can be used.
• the laminate according to the present disclosure can be produced by using a metal layer or metal wiring as a support in the method for producing a polymer film according to the present disclosure.
• a metal layer or metal wiring may be provided by thermocompression bonding or the like on the surface of the polymer film opposite to the side on which the support is provided.
• the thermocompression temperature is preferably 140°C to 300°C, more preferably 160°C to 280°C, and even more preferably 210°C to 240°C.
• the time for the thermocompression bonding is preferably 10 minutes to 300 minutes, more preferably 30 minutes to 240 minutes, and even more preferably 45 minutes to 180 minutes.
• A1 Hydrogenated styrene-isobutylene-styrene block copolymer (product name "SIBSTAR103T-UL", manufactured by Kaneka Corporation) swollen with N-methylpyrrolidone, frozen and ground, average particle size 5.0 ⁇ m (D50)
• A2 Polyethylene particles (product name "Flow Beads CL-2080", manufactured by Sumitomo Seika Chemicals, median particle diameter 11 ⁇ m)
• the aromatic polyesteramide P1a was heated in a nitrogen atmosphere from room temperature to 160°C over 2 hours and 20 minutes, then heated from 160°C to 180°C over 3 hours and 20 minutes, and held at 180°C for 5 hours to carry out solid-state polymerization, and then cooled.
• the aromatic polyesteramide P1b was then pulverized in a pulverizer to obtain a powdered aromatic polyesteramide P1b.
• the flow-initiation temperature of the aromatic polyesteramide P1b was 220°C.
• the aromatic polyester amide P1b was heated in a nitrogen atmosphere from room temperature to 180°C over 1 hour 25 minutes, then heated from 180°C to 255°C over 6 hours 40 minutes, and held at 255°C for 5 hours to carry out solid-state polymerization, and then cooled to obtain a powdered aromatic polyester amide P1.
• the flow initiation temperature of the aromatic polyesteramide P1 was 302° C.
• the melting point of the aromatic polyesteramide P1 was measured using a differential scanning calorimeter and found to be 311° C.
• the dielectric tangent of the aromatic polyesteramide P1 was 0.003.
• F1 Liquid crystal polymer particles (average particle size 7 ⁇ m, melting point 334° C.) prepared according to the following production method.
• F2 Crushed liquid crystal polymer particles
• F1 (average particle size 3 ⁇ m, melting point 334° C.)
• F3 Boron nitride particles (product name "SHP-7", manufactured by Mizushima Ferroalloy Co., Ltd., average particle size 2 ⁇ m, melting point 2900° C.)
• F4 Liquid crystal polymer particles (product name "UENO LCP A-8100" crushed product, Ueno Pharmaceutical Co., Ltd., average particle size 5 ⁇ m, melting point 220° C.)
• acetic anhydride (1.08 molar equivalent relative to the hydroxyl group) was further added. Under a nitrogen gas stream, the temperature was raised from room temperature to 150°C over 15 minutes while stirring, and refluxed at 150°C for 2 hours. Next, while distilling off the by-produced acetic acid and unreacted acetic anhydride, the temperature was raised from 150° C. to 310° C. over 5 hours, and the polymer was taken out and cooled to room temperature. The obtained polymer was heated from room temperature to 295° C. over 14 hours, and solid-state polymerized at 295° C. for 1 hour. After the solid-state polymerization, the mixture was cooled to room temperature over 5 hours.
• ⁇ Copper foil> M1A Product name "CF-T9DA-SV-18", manufactured by Fukuda Metal Foil & Powder Co., Ltd., copper foil having a layer C of 3 ⁇ m in thickness formed on the treated surface with an average thickness of 18 ⁇ m by the following method - Formation of Layer C - 8 parts by mass of aromatic polyesteramide P1 was added to 92 parts by mass of N-methylpyrrolidone and stirred at 140° C. for 4 hours under a nitrogen atmosphere to obtain a solution of aromatic polyesteramide P1 (solid content concentration: 8% by mass). A solution was prepared by mixing 9.96 parts by mass of the aromatic polyesteramide P1 solution with 0.04 parts by mass of an aminophenol-type epoxy resin (product name "jER630", manufactured by Mitsubishi Chemical Corporation).
• M1B Product name "CF-T9DA-SV-18", manufactured by Fukuda Metal Foil & Powder Co., Ltd., average thickness 18 ⁇ m
• M2 Product name "MT18FL”, manufactured by Mitsui Mining & Smelting Co., Ltd., average thickness 1.5 ⁇ m
• M3 Product name "CF-T49A-DS-18", manufactured by Fukuda Metal Foil & Powder Co., Ltd., average thickness 18 ⁇ m
• a solution for forming layer A and a solution for forming layer B were prepared to produce a polymer film.
• a solution for forming Layer A was prepared by Mixing Method A or Mixing Method B.
• (1) Mixed Method A The polymers and fillers shown in Table 1 were mixed in the contents (mass%) shown in Table 1, N-methylpyrrolidone was added to adjust the solids concentration to 25 mass%, and the mixture was stirred with a magnetic stirrer for 10 hours to obtain a solution for forming Layer A.
• (2) Mixed Method B The polymers and fillers shown in Table 1 were mixed in the contents (mass %) shown in Table 1, and N-methylpyrrolidone was added to adjust the solids concentration to 25 mass %.
• thermocompression bonding machine product name “MP-SNL”, manufactured by Toyo Seiki Seisakusho Co., Ltd.
• MP-SNL manufactured by Toyo Seiki Seisakusho Co., Ltd.
• the carrier copper foil was peeled off.
• thermocompression bonding at 230° C. and 4 MPa for 60 minutes using a thermocompression bonding machine (product name “MP-SNL”, manufactured by Toyo Seiki Seisakusho Co., Ltd.) to produce a four-layer copper-clad laminate.
• thermocompression bonding machine product name "MP-SNL", manufactured by Toyo Seiki Seisakusho Co., Ltd.
• MP-SNL manufactured by Toyo Seiki Seisakusho Co., Ltd.
• the substrate was exposed to light so that the wiring pattern remained, developed, etched, and the dry film was removed to produce a substrate A with a wiring pattern having a line/space of 100 ⁇ m/100 ⁇ m including a ground line and three pairs of signal lines on both sides of the substrate.
• the length of the signal line was 50 mm, and the width was set so that the characteristic impedance was 50 ⁇ .
• a copper foil (product name "MT18FL", average thickness 1.5 ⁇ m, with carrier copper foil (thickness 18 ⁇ m), manufactured by Mitsui Mining & Smelting Co., Ltd.) and a liquid crystal polymer film (product name "CTQ-50", average thickness 50 ⁇ m, manufactured by Kuraray Co., Ltd.) were prepared as a substrate.
• the copper foil and the substrate were stacked in this order so that the treated surface of the copper foil was in contact with the substrate.
• a laminator product name "Vacuum Laminator V-130", manufactured by Nikko Materials Co., Ltd.
• thermocompression bonding machine product name "MP-SNL", manufactured by Toyo Seiki Seisakusho Co., Ltd.
• MP-SNL manufactured by Toyo Seiki Seisakusho Co., Ltd.
• the carrier copper foil on the opposite side of the substrate of the single-sided copper-clad laminate was peeled off, and the surface of the exposed 1.5 ⁇ m copper foil was roughened and a dry film resist was attached. After pattern exposure and development, plating was performed on the area where the resist pattern was not arranged. Furthermore, the dry film resist was peeled off, and the copper exposed by the peeling process was removed by flash etching to produce a substrate B with a wiring pattern having a line/space of 20 ⁇ m/20 ⁇ m.
• the prepared substrate having a wiring pattern was superimposed on the layer B side of the prepared single-sided copper-clad laminate, and hot pressed at 160° C. and 4 MPa for 1 hour to obtain a wiring board.
• the obtained wiring board had a wiring pattern (ground line and signal line) embedded therein, and when substrate A with a wiring pattern was used, the thickness of the wiring pattern was 18 ⁇ m, and when substrate B with a wiring pattern was used, the thickness of the wiring pattern was 12 ⁇ m.
• the cross section of the double-sided copper-clad laminate was exposed using a cryomicrotome.
• layers A and B were identified, and the elastic modulus of layers A and B at 160°C and the elastic modulus of layer B at 25°C were measured as the indentation elastic modulus using a nanoindentation method.
• the indentation elastic modulus was measured by applying a load at a loading rate of 0.28 mN/sec with a Vickers indenter using a microhardness tester (product name "DUH-W201", manufactured by Shimadzu Corporation), holding the maximum load of 10 mN for 10 seconds, and then unloading at a loading rate of 0.28 mN/sec.
• the cross-sectional sample was measured at 20 arbitrary positions at 160°C or 25°C, and the average value was taken as the elastic modulus.
• the surface roughness Rc of the side of Layer A on which Layer B was disposed was measured by exposing a cross section of the double-sided copper-clad laminate with a cryomicrotome, extracting the interface of Layer A on the Layer B side with an optical microscope, and measuring the average height Rc in accordance with JIS B0601 2001.
• the evaluation length was 500 ⁇ m.
• the cross section of the double-sided copper-clad laminate was exposed using a cryomicrotome.
• the cross section was observed in 100 fields of view at 10,000 times magnification using a scanning electron microscope (SEM), and 100 particles were randomly selected. The lengths of the selected particles in the major axis direction were measured, and the average value was taken as the average particle size of the particles.
• the copper foil of the double-sided copper-clad laminate was removed with an aqueous solution of ferric chloride, washed with pure water, and dried to obtain a polymer film, which was then used for the measurement.
• the dielectric loss tangent was measured at a frequency of 10 GHz by a resonance perturbation method.
• a 10 GHz cavity resonator (Kanto Electronics Application Development Co., Ltd., "CP531") was connected to a network analyzer (Agilent Technology, Inc., "E8363B”), and the polymer film was inserted into the cavity resonator.
• the dielectric loss tangent of the polymer film was measured from the change in resonance frequency before and after insertion for 96 hours under an environment of 25°C temperature and 60% RH.
• the metal layer of the prepared double-sided copper-clad laminate was electrolytically plated to a thickness of 50 ⁇ m.
• the support side was fixed to a flat plate with double-sided adhesive tape, and the metal layer was peeled from the double-sided copper-clad laminate at a speed of 50 mm/min in an environment of 25° C. and 50% relative humidity by the 90° method according to JIS C 5016 (1994), and the peel strength (kN/m) between Layer B and the metal layer was measured.
• the four-layer copper-clad laminate was cut into a size of 30 mm x 30 mm to prepare an evaluation sample.
• the evaluation sample was treated for 168 hours in a thermohygrostat at a temperature of 85°C and a relative humidity of 85%.
• the evaluation sample was then placed in an oven set at 260°C and heated for 15 minutes.
• the evaluation sample after heating was cut with a razor, and the cross section was observed with an optical microscope, and the peeling state was visually evaluated.
• A No distortion of the laminate was observed, and no peeling was observed between Layer B and the copper foil.
• B Distortion of the laminate was observed, but no peeling was observed between Layer B and the copper foil.
• C Peeling was observed between Layer B and the copper foil with a width of 0.1 mm or less.
• D Peeling was observed between layer B and the copper foil with a width of more than 0.1 mm.
• Examples 1 to 7 include a layer A and a layer B disposed on at least one surface of layer A, and layer A has a surface roughness Rc of 5 ⁇ m or less on the side where layer B is disposed, and layer B includes a material a having an elastic modulus of less than 0.10 MPa at 260°C and a material b having an elastic modulus of 0.10 MPa or more at 260°C, and has an elastic modulus of 500 MPa or less at 25°C and an elastic modulus of 0.60 MPa or less at 160°C, and a dielectric dissipation factor of 0.01 or less, and therefore has excellent step conformability and heat resistance.
• layer B did not contain material b, and it was found to have poor heat resistance.
• layer A contains particles with a melting point of 300°C or higher, and it was found that this has superior heat resistance compared to Example 7.
• Example 2 the particles contained in Layer A that have a melting point of 300°C or higher have an average particle size of 4.0 ⁇ m or less, and it was found that the heat resistance was superior to that of Example 1.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Mechanical Engineering (AREA)
• Laminated Bodies (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (1)

Family

ID=93938089

Family Applications (1)

Country Status (2)

Citations (5)

• 2024
  • 2024-05-15 JP JP2025529504A patent/JPWO2025004587A1/ja active Pending
  • 2024-05-15 WO PCT/JP2024/018013 patent/WO2025004587A1/ja not_active Ceased

Patent Citations (5)

Also Published As

Similar Documents

Legal Events