Patent ID: 7364799

Claim:
A flexible metal-clad laminate consisting essentially of a layer of a polyamide-imide resin laminated on at least one side of a metal foil, wherein the polyamide-imide resin is a copolymerized polyamide-imide that consists essentially of constitutional units represented by Formulae (1), (2), and (3) shown below: wherein R 1 and R 2 are the same or different, and independently represent hydrogen or C 1-4 alkyl or alkoxy; and Y represents a direct linkage or ether linkage; wherein R 3 and R 4 are the same or different, and independently represent hydrogen or C 1-4 alkyl or alkoxy; and wherein R 5 and R 6 are the same or different, and independently represent hydrogen or C 1-4 alkyl or alkoxy, and wherein the polyamide-imide resin satisfies the molar ratios of Formula (1)/Formula (2)=1/99 to 99/1 and [Formula (1) +Formula (2)]/Formula (3)=30/70 to 1/99.