| 摘要 |
PURPOSE: A composition of lead-free solder ball alloy is provided to apply efficiently a solder ball to an adhering object of a semiconductor chip by excluding Pb and Cd as harmful components to a body and reducing thermal difference between a liquidus line and a solidus line. CONSTITUTION: Metal components such as Sn and Ag are used as main components. An alloy is fabricated by mixing one or more components of Ge and Se with the main components of Sn and Ag. The alloy is formed with Ag of 3.0 to 3.8 weight percent, Ge of 0.005 to 0.009 weight percent, Se of 0.005 to 0.009 weight percents, and Sn of the remaining weight percent. In a range of a melting temperature, thermal difference between a liquidus line and a solidus line does not exceed 5 degrees centigrade.
|
