摘要 |
Provided is a ball bonding wire of a high-purity copper alloy, the wire having a high recrystallization temperature and being easily produced through wiredrawing with a die at room temperature. The ball bonding wire has a low initial ball hardness and causes no breakage of IC chips. Phosphorus (P) is added in an amount as slight as 0.5-15 mass ppm to high-purity copper having a purity of 99.9985 mass% or higher to thereby produce a copper alloy which has a higher recrystallization temperature than high-purity copper having a purity of 99.9999 mass% or higher and which has a lowered initial ball hardness in ball bonding. Those characteristics are thus achieved. Alternatively, phosphorus (P) is added in an amount as slight as 0.5-15 mass ppm to high-purity copper having a purity of 99.9985 mass% or higher, and the total amount of any other impurities contained in the copper is reduced to a value lower than the phosphorus (P) content. Those characteristics are thereby achieved. |