Method of forming a lead-free tin-silver-copper based solder alloy on an electronic substrate

摘要

A method of forming a lead-free solder alloy on an electronic substrate. In the method, a metal stack which includes a thick nickel barrier layer and an outer copper layer is then evaporated or plated with silver and tin. Upon heating to an appropriate temperature, the copper, tin and silver form a lead-free tin, silver, copper solder.