To provide the manufacturing method of a bonding wire for semiconductor elements wherein the rectilinear advance quality, the elongation percentage, and the tensile strength of the bonding wire are excellent, and its leaning faultiness can be suppressed.
In the wire-diameter contracting and wire drawing works of a bonding wire, the area degression factors of the dies of the respective works are set to 5-25%, and the bonding wire is subjected to the wire-diameter contracting and wire drawing works under the condition of the difference between the maximum and minimum values of the area degression factors being not larger than 12%. Further, a mean area degression factor, an annealing speed in a final continuous anneal, and a furnace length satisfy the relation of the annealing speed (m/min)≤ the furnace length (cm)/(the mean area degression factor (%)/5)2. Hereupon, it is desirable to add to the bonding wire Be of 2-15 mass ppm and rare earth elements of 10-50 mass ppm in total of them.
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