| 摘要 |
An ultrafine wire having a diameter of 20 µm or less for ball bonding, with which bonding can be successively conducted hundreds of thousands of times. Ca, Mg, and La are incorporated as minor additive elements in a concentration of 5-50 mass ppm each into an alloy matrix obtained by incorporating one or more of Pd, Pt, and Cu that have a high purity of 3N or above, in a total concentration of 5-2 mass%, into gold that has a high purity of 5N or above. Alternatively, Be is further incorporated in a concentration of 1-20 ppm, and/or one or more of Ce, Y, and Eu are further incorporated in a total concentration of 1-30 mass ppm. Furthermore, the total concentration of these minor additive elements may be regulated to 100 ppm or less. Thus, the additive elements are inhibited from segregating in the surface of the melt ball, and deposits or oxides of the additive elements are inhibited from accumulating on the capillary tip during bonding and thereby increasing the sliding resistance of the wire during loop formation. Since the surface of the capillary tip is kept smooth, bonding failures in the wire bonding, such as neck damage and nonbonding, are inhibited from occurring and long-term continuous bonding is rendered possible. |
