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Sn-Cu-Ni系合金作为一种低成本的无铅无银钎料愈来愈受到电子封装界的重视。研究了在Sn-0.7%Cu-0.05%Ni(质量分数)合金中添加不同含量(质量分数0.05%~0.50%)的La-Ce混合稀土后钎料合金系的熔化特性、凝固过冷行为、组织演化规律及润湿性能变化。结果表明,添加微量La-Ce混合稀土可明显降低Sn-Cu-Ni系钎料的凝固过冷度,而凝固过冷度的降低使钎料凝固时初生η-(Cu,Ni)6Sn5块状金属间化合物(IMC)相的生长得到抑制,同时钎料中β-Sn相形态由树枝晶逐渐转变为等轴晶;润湿角测定结果表明,La-Ce混合稀土添加量为0.05%时,钎料在Cu基板上呈现优良的润湿性能。
Sn-Cu-Ni alloy as a low-cost lead-free silver-free solder more and more attention by the electronic packaging industry. The melting behavior, solidification and undercooling behavior of the solder alloy after adding La-Ce mixed rare earth with different contents (mass fraction 0.05% ~ 0.50%) to Sn-0.7% Cu-0.05% Ni (mass fraction) Tissue evolution and wettability changes. The results show that the addition of a small amount of La-Ce rare earth can significantly reduce the solidification undercooling of Sn-Cu-Ni brazing filler metal, while the reduction of solidification undercooling makes the brazing alloy solidified η- (Cu, Ni) 6Sn5 bulk The growth of intermetallic compound (IMC) phase was inhibited, while the morphology of β-Sn phase in brazing filler metal gradually changed from dendrites to equiaxed grains. The results of wetting angle measurement showed that the addition of La-Ce mischmetal was 0.05% The solder shows excellent wettability on the Cu substrate.