| 摘要 |
PURPOSE:To improve the heat resistance of a bump electrode by forming the electrode of lead-tin-silver alloy, thereby connecting the electrode by a heat treatment of the temperature similar to the other circuit element. CONSTITUTION:An oxidized silicon film 2, an aluminum wiring film 3 and a surface protective film 4 made of dioxidized silicon or nitrided silicon or the like are laminated on a silicon substrate 1. A multilayer metal film made of chromium, copper, gold or titanium, copper, nickel layers 6, 7, 8 are, for example, covered sequentially in this sequence from the side of the substrate 1 on the window 5 opened at the film 4. A layer of lead-tin-silver alloy containing 60-65% by weight of tin, 1.5-4% by weight of silver is laminated by depositing or plaing on the film 8. Subsequently, the alloy layer is molten by heat treatment or is molten and alloyed at the component metal layers, thereby forming a semispherical bump electrode 9. |
