| 摘要 |
PURPOSE:To provide a bonding wire in which neck cutting by a heat cycle is prevented by forming the covered zone of high pure copper on the outer circumference of the core wire of a copper alloy incorporated with limited ratio of Zr. CONSTITUTION:The core wire zone 1 is formed from the copper alloy in which the recrystallization temp. is increased by incorporating 20-200wt.ppm Zn into high pure copper having >=99.99wt.% purity. The outer circumference of said core wire 1 is covered by the covered zone 2 of the high pure copper having >=99.99% purity to form the bonding wire 1. The concn. of the elements involved in the copper alloy of the core wire zone 1 is dissolved and diluted in the case of forming a ball by fusing the tips together at the time of bonding. The hardness of the ball is therefore regulated to the suitable value and chip cracks can be prevented. The thermocompression bonding and ultrasonic compression bonding with an outer lead can be easily executed as well since the soft high pure copper is used for the covered zone 2. |
