Patent ID: 11351755

Abstract:
A metal-clad laminate includes an insulating layer including a cured product of a resin composition, and a metal foil disposed on at least one principal surface of the insulating layer. The resin composition includes a thermosetting curing agent and a polyphenylene ether copolymer. The polyphenylene ether copolymer has an intrinsic viscosity ranging from 0.03 dl/g to 0.14 dl/g, inclusive. The intrinsic viscosity is measured in methylene chloride at 25° C. And the polyphenylene ether copolymer has, at a molecular terminal, a group represented by one of formula (1) and formula (2) at an average number of more than or equal to 0.8 and less than 1.5 per one molecule. Further, the metal foil includes a barrier layer containing cobalt on a first surface of the metal foil. The first surface is in contact with the insulating layer, and has a ten-point average roughness (Rz) of less than or equal to 2.0 μm. In formula (1), R1 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R2 represents an alkylene group having 1 to 10 carbon atoms. In formula (2), R3 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.