【摘要】 研究了添加稀土元素钐(质量分数为0,0.025%,0.05%,0.1%,0.2%),对无铅钎料Sn-3.5Ag-1.5Bi/Cu润湿性、界面组织和焊点剪切强度的影响。结果表明,在钎料中添加适当的钐元素,可以提高其润湿性,含量为0.1%时,钎料的铺展面积最大为56.742 mm~2。随着钐元素的加入,金属间化合物(IMC)得到细化,当钐含量为0.025%时,金属间化合物厚度最薄为3.461μm。此时,剪切强度最大为91.67 MPa。几个成分条件下,接头断口均呈韧窝状,断裂方式为韧性断裂。更多还原

【Abstract】 The effect of rare earth Sm(0,0.025,0.05,0.1,0.2 wt,%) on wettability,interface microstructures and shear strength of the soldered joint with lead-free solder Sn-3.5Ag-1.5Bi/Cu were investigated.The results indicate that the appropriate amount of rare earth Sm can improve the wettability of solders and the spreading area of solder is 56.742 mm~2 at 0.1%rare earth Sm in content.With the addition of Sm,intermetallic compounds(IMCs) are refined and the thinnest IMC is 3.461 μm,when the content of Sm is 0.025%.Meanwhile,the shear strength of soldered joint with Sn-3.5Ag-1.5Bi-0.025Sm/Cu reaches up to 91.67 MPa.Under the condition of several components,the joint fracture surfaces show dimples,and fracture mode is ductile fracture.更多还原