Patent ID: 6866919

Claim:
A heat-resistant-film-inserted B-stage resin composition sheet for lamination, comprising a heat-resistant film and B-stage resin composition layers for lamination formed on both surfaces of the heat-resistant film, wherein: i. the thickness of the heat-resistant film is 4 to 20 μm, ii. the thickness of the B-stage resin composition layer on one surface of the heat-resistant film is 5 to 10 μm and the thickness of the B-stage resin composition layer on the other surface of the heat-resistant film is 10 to 100 μm, iii. the resin composition to be attached to at least one surface of the heat-resistant film, contains, as an essential component, a resin component containing (a) a polyfunctional cyanate ester monomer and/or a polyfunctional cyanate ester prepolymer in an amount of 100 parts by weight, (b) an epoxy resin which is liquid at room temperature in an amount of 15 to 500 parts by weight and (c) a heat-curing catalyst in a ratio of 0.005 to 10 parts by weight per 100 parts by weight of (a)+(b), and iv. the heat-resistant film is one member selected from the group consisting of a polyimide film, a liquid crystal polyester film and a wholly aromatic polyamide film.