Ag-4Pd键合合金线性能和组织对键合强度的影响

Effects of Ag-4Pd alloy bonding wire properties and structure on bonding strength

摘要:

利用扫描电镜、强度测试仪、热导率测试仪分析了Ag-4Pd和Ag-4Pd-0.5Ru键合合金线性能及组织差异,研究了微量Ru元素对Ag-4Pd键合合金线球焊点尺寸、焊点形貌及键合强度的影响。研究结果表明：Ru元素的加入使Ag-4Pd键合合金线热导率由403 W/m?k降低到385 W/m?k,Ag-4Pd-0.5Ru键合合金线无空气焊球(Free Air Ball)形状较Ag-4Pd键合合金线规则,提高了键合合金线焊点连接强度；Ag-4Pd键合合金线中的Ru元素使其热影响区长度由50μm减少至35μm,消除了由于热影响区长度过大导致的颈部微裂纹缺陷；Ag-4Pd键合合金线中的Ru元素细化了晶粒,增加了相同体积内不同取向的金属晶粒数目,改善了变形时的协同作用,降低了形变的不均匀性程度,获得了较规则的Ag-4Pd键合合金线球焊点形貌。

Abstract:

The different of Ag-4Pd and Ag-4Pd-0.5Ru alloy bonding wire properties and structure were analyzed by scanning electron microscope, strength tester and thermal conductivity tester, the effects of Ru on Ag-4Pd alloy bonding wire ball size, bonded micro phonology and bonded strength were investigated. The results show that the thermal conductivity of Ag-4Pd alloy bonding wire decreases from 403 W/m?k to 385 W/m?k because of doping Ru, and the free air ball shape of Ag-4Pd-0.5Ru alloy bonding is more uniform than Ag-4Pd alloy bonding wire, the Ag-4Pd-0.5Ru alloy bonding wire bonded strength is higher than AgA1 alloy bonding wire. The heat affect zone length decreases from 50μm to 35μm because of doping Ru, and the ball neck crack defect cause of excessive long heat affect zone length will decrease. For Ag-4Pd alloy bonding wire, Ru can refine the grain, then the grain size decreases, and the grain quantity increases, then the inhomogeneous deformation of different grain decrease, and the ball bonded shape is uniform.