快速冷却和扩散退火对Sn-Bi-X焊料的影响  

Influence of rapid cooling and diffusion annealing on Sn-Bi-X solder

作　　者：李元山[1] 陈振华[1] 雷小娟[1] 

机构地区：[1]湖南大学材料科学与工程学院

出　　处：《中国有色金属学报》2007年第8期1319-1323,共5页The Chinese Journal of Nonferrous Metals

摘　　要：通过对自行研制的Sn-Bi-X(X=Ag,Cu,Ge,Ce,Sb)无铅焊料进行快速冷却及扩散退火处理,研究其显微观组织和性能的变化。结果表明,冷却速度越大,熔点越低,共晶比例越小。当甩带速度为1 000 r/min时,熔点由190.5℃降低至186.2℃,且Sn-58Bi共晶相完全消失。扩散退火能消除Bi的粗化晶体,使组织均匀,增强焊料的力学性能,并且退火后组织稳定。扩散退火可以作为表面贴装生产工艺流程的一个工序,退火工艺以125℃保温16 h为宜。A self-fabricated Sn-Bi-X（X=Ag, Cu, Ge, Ce, Sb） lead-free solder was treated by rapid cooling and diffusion annealing, the changes of its microstructures and properties were investigated. The results show that, the faster the cooling rate, the lower the melting point and the smaller the percent of eutectic is. When the melt spinning rate is up to 1 000 r/min, the melting point decreases from 190.5 ℃ to 186.2 ℃, and the eutectic phase of Sn-58Bi disappears fully. Diffusion annealing can remove the coarse crystal of Bi, uniform the microstructure and enhance the mechanical property of Sn-Bi lead-free solder. The microstructure is stable after annealing. Diffusion annealing can be a procedure of surface mounting production process. Annealing at 125 ℃ for 16 h was approved well.

关 键 词：Sn-Bi系无铅焊料 偏析 快速冷却 扩散退火 

分 类 号：TG406[金属学及工艺—焊接]