Abstract: Provided are a novel insulating material for a circuit substrate and a novel metal foil-clad laminate, and the like, in which the anisotropy of coefficients of linear thermal expansion in a MD direction, a TD direction, and a ZD direction is reduced. An insulating material for a circuit substrate, comprising a thermoplastic liquid crystal polymer film, wherein ratios of average coefficients of linear thermal expansion in a MD direction, a TD direction, and a thickness direction (CTEMD, CTETD, CTEZ) at 23 to 200° C., as measured by a TMA method according to JIS K7197, satisfy the following expressions (I) to (III): 0.5?CTEMD/CTETD?1.5 ??(I) 0.10?CTEMD/CTEZ?1.00 ??(II) 0.10?CTETD/CTEZ?1.00 ??(III).

Abstract: Provided are an insulating material for a circuit substrate, which has excellent dielectric characteristics in a high frequency area, has low coefficients of linear thermal expansion all in a MD direction, a TD direction, and a ZD direction, is easily manufactured and has excellent productivity, and a method for manufacturing the same and a metal foil-clad laminate. An insulating material for a circuit substrate, comprising a laminate having a thermoplastic liquid crystal polymer film and a woven fabric of an inorganic fiber, wherein the thermoplastic liquid crystal polymer film contains an inorganic filler, and the laminate is a dry laminate in which the thermoplastic liquid crystal polymer film and the woven fabric are thermocompression bonded.

Abstract: A cover film having at least (A) a substrate layer, (B) an intermediate layer, (C) an adhesive layer, and (D) a heat seal layer having a heat sealable resin, a thermoplastic resin of the (D) heat sealing layer having a mixture of two types of (meth)acrylic acid ester copolymers having different glass transition temperatures and a hydrazide compound, wherein one of the (meth)acrylic acid ester copolymer in the (meth)acrylic acid ester copolymer mixture has a glass transition temperature of ?20 to 10° C. and the other (meth)acrylic acid ester copolymer has a glass transition temperature of 40 to 80° C.

Abstract: A method of producing a double-sided metal-clad laminate comprises a supplying step of supplying an insulating film interposed between two metal foils continuously to between a pair of endless belts, a heat and pressure applying step of forming a laminate of the insulating film and the metal foils by heating and applying a pressure to the insulating film and the metal foils under predetermined condition while the insulating film is interposed by the two metal foils in between the endless belts, and a cooling step of cooling the laminate, wherein the insulating film has a thickness of 10 to 500 ?m, a degree of planar orientation of 30% or more, an average coefficient of linear expansion in an MD direction of ?40 to 0 ppm/K and an average coefficient of linear expansion in a TD direction of 0 to 120 ppm/K.

Abstract: A method of producing a thermoplastic liquid-crystal polymer film includes forming a thermoplastic liquid-crystal polymer film having opposite surfaces by molding a thermoplastic liquid-crystal polymer, melting the thermoplastic liquid-crystal polymer film by heating the thermoplastic liquid-crystal polymer film with the opposite surfaces being in contact with two support sheets at a temperature of from a melting point of the thermoplastic liquid-crystal polymer to a temperature higher than the melting point by 70° C., cooling the melted thermoplastic liquid-crystal polymer film to a temperature equal to or less than a crystallization temperature of the thermoplastic liquid-crystal polymer at a cooling rate of from 3° C. per second to 7° C. per second, and separating the cooled thermoplastic liquid-crystal polymer film from the support sheets.

Abstract: A cover film having at least (A) a substrate layer, (B) an intermediate layer, (C) an adhesive layer, and (D) a heat seal layer having a heat sealable resin, a thermoplastic resin of the (D) heat sealing layer having a mixture of two types of (meth)acrylic acid ester copolymers having different glass transition temperatures and a hydrazide compound, wherein one of the (meth)acrylic acid ester copolymer in the (meth)acrylic acid ester copolymer mixture has a glass transition temperature of ?20 to 10° C. and the other (meth)acrylic acid ester copolymer has a glass transition temperature of 40 to 80° C.