铁氧体表面无铅焊接薄膜的磁控溅射制备研究

Growth of Lead-Free Welding Films on Ferrite Substrate by Magnetron Sputtering

随着环保要求的不断提高,特别是2006年欧盟新环保指令禁止电子产品含有铅、六价铬等重金属,铁氧体以往的电镀焊接薄膜将被明确禁止。本文采用磁控溅射技术在铁氧体表面制备无铅焊接复合薄膜,从理论和实验上研究分析了薄膜的结构、厚度与膜层的结合、焊接性能。研究发现:当膜层结构为Cr(150 nm)/Ni-Cu(460 nm)/Ag(200 nm)时,其平均抗拉强度可达6.15 MPa,焊接合格率大于98%,能经受450℃1、0 s的高温无铅焊锡熔蚀,性能远远好于电镀膜层,而且工艺无污染。

Various metallic films, including Ag, Ni, Cu, Cr and Ni-Cu alloy, were deposited by magnetron sputtering on ferrite substrates for the purpose of lead-free welding of the ferrites. The micmstructures of the f＇dms and the interface were characterized with X-my diffraction （XRD） energy dispersive spectroscopy （EDS） and metaUographic microscopy. The influence of the microstructures, films thickness and interfacial adhesion of the composite films on welding was evaluated. The results show that lead-free welding of ferrites can be realized by the newly-developed technique. We found that the Cr（ 150 nm）/Ni-Cu（460 nm）/Ag（200 nm） multi-layers films work best for the welding. The environmental friendly welding films have an average bonding strength of 6.15 MPa,and a welding acceptability over 98% with performance better than that of all the electroplating. In addition, it can withstand the soakage of lead-free solder at 450 ℃ for 10 s.