无铅钎焊界面反应及其对可靠性的影响

在钎料和衬底之间形成的界面层的质量对于整个焊接所要求的电气性能或机械性能有着至关重要的影响,从界面发生的反应入手,对4种无铅焊料的界面反应和特性进行了讨论.研究了界面层厚度随钎焊时间变化的关系,并对再流过程中峰值温度和液化温度以上保持时间对钎焊点机械性能的影响进行了实际测量.实验结果证明了焊接界面对于可靠性有重要影响.

The Interfacial Reactions and Realibility with Lead(Pb)-Free Solders

Solder interconnection technology plays a very important role in microelectronics packaging.An ideal connection means good electrical property and mechanical strength.The quality of interfacial layer between the solder and substrate is related tightly with the electrical and mechanical properties of solder interconnection.The interfacial reaction and characteristics of four different kinds of lead-free solder were discussed.The relation between the thickness of interfacial layer and soldering time was measured.Moreover,the mechanical property of interconnection was measured corresponding to different reflow curve(which includes the peak temperature and the remaining time above liquid temperature). The results demonstrate that on the substrate of Ni/Au coated,the shear strength of lead-free solders is very sensitive to the reflow curve.