| 摘要 |
Tin-lead alloy balls for packaging semiconductors are made by cutting a tin-lead alloy rod into particles, placing the particles in a liquid where they soften and become ball-shaped in an upper region of the liquid and cool as they sink, shaping the balls at normal temperature in a liquid, cleaning the shaped balls, sorting the cleaned balls according to circularity and diameter, removing static charge from the sorted balls and then packing in a nitrogen atmosphere. |
