Bleifreie Niedertemperaturlegierung und Verfahren zur Bildung einer mechanisch überlegenen Verbindung unter Verwendung dieser Legierung

摘要

Solder bumps are formed on a substrate including solder wettable regions by positioning a mask of non wettable material over the substrate then loading it with a solder paste of composition bismuth-tin-X, where X is a compound of silver or indium, and then reflowing the solder to form solder bumps on the substrate before removing the mask. The preferred solder alloy is tin-48%, silver or indium-0.5 to 2.0%, bismuth-50 to 51.5%.