| 摘要 |
PURPOSE:To improve bonding strength and ensure hermetic sealing of super conductive connecting part by providing an intermediate metal film of normal conductor in the periphery of connecting interface between superconductive electrode and super conductive solder. CONSTITUTION:An intermediate metal film 1 is vacuum-deposited on an electrode 4, a metal mask 6 having a window 6a is placed closely to Si substrate 3 and the center area of electrode 4 is exposed by removing the intermediate metal film 1 at the area of window 6a by the Ar ion etching. Thereafter, the superconductive solder 2 is vacuum-deposited using the metal mask 6 and the metal mask 6 is then removed. Next, flux is coated on the intermediate metal film 1 and superconductive solder 2. The surface of intermediate metal film 1 is coated with the solder 2 and thereby superconductive connecting solder bump can be obtained. This solder bump is formed on the chip mounting elements which operates at a low temperature and wiring substrate and the flip chip bonding is carried out. Thereby, a large bonding strength is obtained and sufficient sealing can also be obtained. |
