【摘要】 表面贴装技术（SMT）正在逐渐向着低温互连的趋势转变,促使低温无铅钎料合金成为行业内关注的焦点之一。Sn-Bi共晶合金由于低熔点（138℃）、高强度、低成本而应用于消费类电子产品封装与组装,但是由于Bi相固有的脆性、时效过程中Bi相的粗化、钎料合金与Cu反应时Bi相在Cu₃Sn/Cu界面的偏析等缺陷的存在阻碍了Sn-Bi共晶钎料合金的广泛应用。降低Sn-Bi共晶合金中的Bi含量可有效改善其力学性能与焊点可靠性。针对低温无铅互连中低Bi含量的Sn-Bi基无铅钎料合金,研究了不同Bi含量下低温无铅钎料的微观组织、硬度、弯曲强度、抗拉强度、延展性以及Sn-Bi基/Cu焊点中界面微观组织、跌落性能与电迁移性能,分析了消费类电子产品封装用低温Sn-Bi基无铅钎料合金的发展方向与研究进展。更多还原

【Abstract】 Surface mounted technology（SMT） is gradually shifting towards low-temperature soldering, which makes low-temperature lead-free soldering one of the main focus in the industry. Sn-Bi eutectic solder, as one of the low-temperature lead-free solder, has been widely used in the modern electronic component assembly due to its low melting point and excellent mechanical properties. However, the brittleness of Bi phase, the coarseness of Bi grains during aging and the segregation of Bi at the Cu₃Sn/Cu interface will hinder its further applications and developments. Lowering the Bi content in Sn-Bi eutectic solder alloy not only keeps the high strength, but also promotes the elongation of the Sn-Bi based solders. In the present work, the microstructure, hardness, bending strength, tensile strength and ductility of Sn-Bi based solder alloys with low Bi content, interfacial microstructure, drop reliability and electromigration performance of SnBi based solder joints are investigated, which would provide guideline for further development and research about Sn-Bi based low-temperature lead-free solder alloy for packaging of consumer electronics.更多还原