| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a copper alloy foil for flexible printed circuit board which has electrical conductivity and is excellent in the evenness after etching a copper foil surface. <P>SOLUTION: The copper alloy foil comprises one or more elements selected from the group consisting of Sn, Ag, In, and Mg as an alloying element in an amount of 300-3,000 ppm in total, and the balance Cu with inevitable impurities. The surface after heat treatment at 300°C for 15 minutes is observed with a view of 100μm×100μm, and the rolled parallel section thereof is observed in the range of a 100μm wide. In both cases, the average crystal grain diameter of a recrystallized part is 5μm or less, and the maximum crystal grain diameter is 10μm or less. Further, the area rate of the crystal grains having a major axis of 5-10μm in the observation area is 20% or less. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
