| 摘要 |
PROBLEM TO BE SOLVED: To provide a structure of a surface property-modified silver palladium alloy wire which allows ultrasonic bonding to be performed with stability without the need for setting bonding conditions individually even if a covering material or core material is changed in kind or wire diameter, and which is wide in process window width at the time of ultrasonic bonding.SOLUTION: A structure of a surface property-modified silver palladium alloy wire comprises: a core material including an alloy of silver (Ag) and gold (Au) which are 99.99 mass% or more in purity, and palladium (Pd) which is 99.9 mass% or more in purity, provided that the alloy consists of an alloy including 1-5 mass% of Ag and Pd or a (Au or Pt) alloy including 1-5 mass% of Ag and 0.05-10 mass% of Pd; and a surface property-modified layer including gold (Au) of 99.99 mass% or more in purity, palladium (Pd), platinum (Pt) or an alloy thereof. The wire has a surface morphology such that deep color rings crossing a longitudinal direction of the wire and spaced apart from one another by a width of 20 to 30 μm are formed together with crystal grain boundaries of the core material, and the surface property-modified layer is embedded in large and small elongated grooves of the core material.SELECTED DRAWING: Figure 1 |
