热—剪切循环条件下Sn3.5Ag0.5Cu/Ni界面化合物生长行为

Growth behavior of compounds at Sn3.5Ag0.5Cu/Ni under thermal-shearing cycling

对热-剪切循环条件下（25—125℃）Sn3．5Ago．5Cu／Ni界面上原子扩散和化合物的生长行为进行了研究，并将其与恒温时效条件下界面化合物的生长行为进行了比较。结果表明，再流焊后，在Sn3．5Ag0．5Cu／Ni界面上形成（CuxNi1-x）6Sn5化合物；随着热-剪切循环周数的增加，（CuxNi1-x）6Sn5化合物形态从笋状向平面状生长；热-剪切循环200周后，（NixCu1-x）Sn3码化合物在（CuxNi1-x）6Sn5化合物周围形成并呈片状快速长大。界面近域的钎料内，颗粒状的Ag3Sn聚集长大成块状。界面金属间化合物的厚度随循环周数的增加而增加，且生长基本遵循抛物线规律，说明Cu原子的扩散控制了（CuxNi1-x）6Sn5化合物的生长。

The atoms diffusion and growth behavior of intermetallic compound(IMC) at Sn3.5Ag0.5Cu/Ni interface after thermal-shearing cycling (25-125 ℃) were investigated,which was compared to compound growth behavior under isothermal aging condition.The results showed that there is a type of(CuxNi1-x)6Sn5 IMC formed at the interface after reflowing,and the morphology of compound changes from scallop-like with the cycling increasing.There is another kind of compound(NixCu1-x)Sn3 formed surrounding(CuxNi1-x)6Sn5 after 200 cycles and grow up rapidly as planarlike.As the thermal-shearing cycling increasing,Ag3Sn formed uniform particles after reflowing congregates to grow up to chunk-like in the solder.The IMC at the interface growth follows a parabolic growth kinetiscs with the thermal-shearing cycling increasing,implying that it was controlled by Cu atom diffusion.