Semiconductor device

Abstract

Abstract PURPOSE:To suppress a fatigue breakdown by a method wherein a shape of a high-melting-point solder bump installed on a semiconductor chip is kept as it is, a low-melting-point solder bump mainly installed on a wiring part of a circuit board is melted and the semiconductor chip is connected electrically to the wiring part of the circuit board. CONSTITUTION:A high-melting-point solder layer composed of 90% of Pb and 10% of Sn is formed on a barrier metal 2 installed on a semiconductor chip 1 by a plating method or the like; this layer is shaped by a wet back method; a nearly spherical solder bump 3 is formed. On the other hand, another barrier metal 2 is installed in a position corresponding to the high-melting-point solder bump 3 on a wiring part 5 installed on a circuit board 4 to mount the semiconductor chip 1; a hill-shaped low-melting-point solder bump 6 composed of 40% of Pb and 60% of Sn is formed on the barrier metal 2 by the plating method. The solder bump 6 is superposed on the high-melting-point solder bump 3; these reflow at 200-230 deg.C; the semiconductor chip 1 is connected electrically to the wiring part 5. During this process, the high-melting.point solder bump 3 keeps its shape as it is and is bonded to the molten low-melting-point solder bump 6.

Inventors

• 👤 Yoshifumi Moriyama

Bibliographic Details