| 摘要 |
Provided is a bonding wire (W) with a wire diameter L of 50.8 µm or less, for connecting an integrated circuit element electrode (a) with the conductor wiring of a circuit wiring board by a ball bonding method. The core (1) contains 10 to 50 mass ppm of P, the remainder being Cu and incidental impurities. A coating layer (2) of Pd with a thickness of t2 from 0.010 µm to 0.090 µm is formed on the entire outer circumference of the core (1) and a carbon concentration layer (3) with a thickness of t3 from 0.0001 µm to 0.0005 µm is further formed on the surface. The ratio of tensile strength TSR at room temperature and tensile strength TSH at 250°C in tensile testing (HR=TSH/TSR × 100) is from 50% to 70%, and the carbon concentration layer (3) is formed by adjusting the degree of cleaning of lubricants at wire drawing. This bonding wire formed by coating Pd over pure copper satisfies the demand to reduce the space between integrated circuits and has stable bonding strength. |
