In situ formation of Cu–Sn–Ni intermetallic nanolayer as a diffusion barrier in preplated lead frames
In situ formation of Cu–Sn–Ni intermetallic nanolayer as a diffusion barrier in preplated lead frames
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DOI：
10.1063/1.2352803
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发表时间：
2006-09
影响因子：
4
通讯作者：
R. Fu;Lilin Liu;Deming Liu;Tong-Yi Zhang
中科院分区：
文献类型：
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作者：
R. Fu;Lilin Liu;Deming Liu;Tong-Yi Zhang
在铜合金基体上先电镀3-4nm厚的锡层，再电镀Ni层，从而阻止铜合金预镀引线框架中铜的外扩散。扩散反应自动形成10-14nm厚的外延状致密（Cu,Ni）3Sn金属间化合物（IMC）层，显著降低了Cu的外扩散，从而显著提高了引线框架的抗氧化和抗腐蚀能力。在250℃时，Cu在IMC中间层中的扩散系数约为1.6×10−22m2∕s。
A technique for impeding Cu outdiffusion in Cu alloy based preplated lead frames has been developed by electroplating a 3–4nm thick Sn layer on a Cu alloy base prior to electroplating a Ni layer. A 10–14nm thick epitaxylike and dense (Cu,Ni)3Sn intermetallic-compound (IMC) layer is automatically formed en route of diffuse reaction, which leads to a drastic reduction in Cu outdiffusion and hence improves significantly the protection of the lead frames against oxidation and corrosion attack. The estimated Cu diffusion coefficient in the IMC interlayer is about 1.6×10−22m2∕s at 250°C.