Effect of Ag Content on Solidification Cracking Susceptibility of Sn-Ag-Cu Solder Joints

摘要

In the present work, the effect of Ag content on solidification cracking susceptibility of Sn-Ag-Cu solder joints has been investigated. Solders containing 1.0 wt.% to 3.8 wt.% Ag were used in the experiment. Solidification cracks were created using a copper self-restraint specimen, which could simulate the process of solidification cracking. Meanwhile, solidification cracking susceptibility was evaluated by comparing the total crack length of the solder joint. The results indicate that solidification cracks exist in solder joints with 1.0 wt.% to 3.0 wt.% Ag content, whereas there are no cracks in Sn-3.8Ag-0.7Cu solder joints. When the Ag content increases from 1.0 wt.% to 3.0 wt.%, the total crack length of Sn-Ag-Cu solder joints increases to a maximum and then drops to zero when the Ag content reaches 3.8 wt.%. In addition, the susceptibility to solidification cracking is observed as follows: SAC207 > SAC305 > SAC107 > SAC387.