Sn-9Zn/Cu焊点的结合强度与抗蠕变性能

基于前期进行的锡锌合金无铅钎料新型助焊剂研究,实验考查了其中二氯化锡活化剂含量水平对Sn-9Zn/Cu焊点剪切强度和常温抗剪切蠕变性能的影响.结果表明:就上述焊点强度而言,二氯化锡含量的影响与它对润湿性的影响5]不尽一致,存在一个最佳的质量分数5%,超过该含量后尽管润湿性还继续提高,上述强度值却均会下降.在二氯化锡质量分数为5%时制得的焊点在剪切实验中呈良好韧性断裂模式.实验还显示:焊剂中较高的松香浓度明显有益于焊点的抗剪切蠕变强度,而对瞬时剪切强度影响不大.

Shear Strength and Creep Behavior of Sn-9Zn/Cu Solder Joints Prepared under New Fluxes

Based on the previous studies of new flux for Sn- 9Zn lead- free electronic solders, effects of SnCl2 activator to shear strength and shear creep resistance of Sn - 9Zn/Cu solder joints were investigated. The results show that the effects of SnCl2 addition on the strength of Sn -9Zn/Cu solder joints are different on their wettability. For the joint strength, an optimum SnCl2 concentration, -5 %, was found. When the SnCl2 content is higher than this level, both the shear strength and the creep resist- ance decrease with increasing SnCl2 content, even though the wettability increase. At 5 % SnCl2, ductile fracture of the solder joint appeared in the shear strength test. It was also found that higher concentration of rosin in flux is beneficial for shear creep resistance of the joints, while its effect on the instantaneous shear strength is less obvious.