铁氧体表面耐高温Ni-V/Ag复合金属化薄膜的研究

Metallization of High-Temperature Resistant Ni-V/Ag Films Deposited on Ferrite Inductors

提出了一种用于铁氧体电感金属化的耐高温薄膜。它采用了Ni-V/Ag复合膜系,能够满足贴片电感组装过程中耐受420℃高温焊接10 s的要求,而且厚度不超过6μm。为了了解焊接中的表面反应过程,用扫描电镜、能量色散X射线光谱仪对不同参数焊接膜层的微观形貌和成分进行了分析测量。结果显示在250℃时金属件化合物主要是(Cu,Ni)6Sn5,而在420℃时则是以(Ni,Cu)3Sn4为主,焊接时的高温能极大地改变表面反应的速率和产物,同时证明所述膜层能达到设计要求。

The Ni-V/Ag composite films, with high temperature resistance, were deposited by magnetron sputtering on substrate of ferrite inductors. Since the surface mounting of ferrite inductor requires a chip thickness about 6μm and a high temperature （420℃） heating for at least 10 s to burnout cladding of Cu wire, metallization of the Ni-V/Ag composite films may be a good solution. The impacts of the soldering conditionson the microstructures of the junction were evaluated. The microstructures and phase structures of the Ni-V/Ag composite films,before and after soldering, were characterized with scanning electron microscopy, and energy dispersive spectroscopy. As the soldering temperature increased to 420℃, the dominant intermetaUic compound （Cu, Ni）6Sn5 phase,observed at 250℃ ,gradually turned into（Ni, Cu）3Sn4 phase. Besides, high soldering temperature promotes favorable surface reactions. We suggest that the 5/an thick Ni-V/Ag film be a good material for industrial production of ferrite inductors.