| 摘要 |
PROBLEM TO BE SOLVED: To obtain Sn-Pb solder balls without faulty appearance by a method of atomizing in oil and to provide a manufacturing method thereof. SOLUTION: In a method of atomizing in oil in which molten solder is discharged from a nozzle tip into oil heated above the melting point of the solder and the liquid stream of the discharged molten solder is divided into pieces in the oil to obtain solder balls, the composition of the molten solder discharged from the nozzle tip is, by weight, 5-100 ppm Fe, 36-37% Pb, and the balance Sn with inevitable impurities. |
