Patent ID: 7704451

Claim:
An aluminum alloy sheet comprising: 0.1% to 0.4% by mass of Cu, 0.5% to 1.5% by mass of Mg, 0.7% to 1.5% by mass of Mn, 0.35% to 0.50% by mass of Fe, and 0.1% to 0.3% by mass of Si, wherein a number density of Al—Mn—Fe—Si-based intermetallic compound having a maximum length of 8 to 15 μm per unit area is 179 grains/mm 2 or less; a number density of Al—Mn—Fe—Si-based intermetallic compound having a maximum length of 10 μm or more per unit area is 67 grains/mm 2 or less; an oxide film having an average thickness of 30 nm or less is formed on the surface of the aluminum alloy sheet; and an arithmetic average roughness Ra of the surface of the aluminum alloy sheet is 0.30 to 0.45 μm.