La对Sn-0.3Ag-0.7Cu回流焊点纳米力学性能影响

随着电子产业的不断发展,对微连接焊点可靠性的要求越来越高. 文中在Sn-0.3Ag-0.7Cu的基础上添加第四种微量元素La,并制备出多种不同铼含量的焊球,通过回流焊得到Sn-0.3Ag-0.7Cu-xLa焊点. 采用纳米压痕仪对焊点进行一次加载—卸载试验,对试验所得到的载荷—位移数据通过采用Ma物理反解析法可得出焊点的纳米压痕硬度H、弹性模量E及蠕变速率敏感指数m等焊点的性能参数.研究稀土元素La对焊点纳米力学性能的影响. 结果表明,随着微量稀土元素La含量的增加,焊点的硬度、弹性模量表现出明显的增长趋势,而且抗蠕变性能随着铼含量的上升呈线性上升趋势.

Effect of La on nano mechanical properties of Sn-0.3Ag-0.7Cu reflow solder joints

With the development of electronic industry, micro solder joints require higher and higher reliability. The Sn-0.3Ag-0.7Cu-xLa joints were obtained by reflow soldering, with Sn-0.3Ag-0.7Cu as the substrate and different contents of La. The effect of La on nano mechanical properties of the soldered joints was studied. The mechanical performance parameters of joints, nano indentation hardness H, elastic modulus E and creep strain rate sensitivity index m, were obtained through Ma geophysical inverse analysis method based on the force-depth data. The results show that the values of hardness and elastic modulus had an obvious tendency of increase with the increase of La content. And the creep resistance of solder joints was improved with the increase of La content.