| 摘要 |
PROBLEM TO BE SOLVED: To provide a new and improved composition of an environment-friendly and lead-free solder alloy. SOLUTION: Lead-free solder alloy contains Sn as a major component and is made of non-poisonous and environment-friendly metal. The lead-free solder includes basically four elements and is composed of approximately 99.0 wt.% Sn, 0.3-0.4 wt.% Ag, 0.6-0.7 wt.% Cu, and has a non-eutectic melting temperature of about 217-227°C. The fourth kind of the elements is non-metal phosphorus (P). By adding 0.01-1.0 wt.% P to the above-mentioned composition, a further increase in the stability of microstructure and a decrease in slugs formation are achieved when manual soldering, wave soldering and hot blast type reflow soldering in the process for installing electronic equipment. COPYRIGHT: (C)2007,JPO&INPIT
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