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随着电子产品无铅化的不断推进,在高可靠电子产品组装中,无铅镀层器件与有铅焊料混合装配焊接的情况不可避免。采用正交实验研究四种不同镀层的QFP器件、三种镀层PCB、两种温度曲线和SnPb焊膏的兼容性,并测定焊点的抗拉强度,采用扫描电镜分析焊点形貌。结果表明,在不同镀层器件的混装实验中,Sn和SnPb镀层焊点强度高于NiPdAu和SnBi镀层焊点;对于纯Sn镀层器件,采用有铅工艺温度曲线能够兼容该类器件的焊接;在实验采用的三种镀层工艺中,含铅热风整平工艺对焊接温度曲线的兼容性最好。
With the continuous advancement of lead-free electronic products, it is unavoidable that the lead-free plating devices and the lead solder should be assembled and soldered in highly reliable electronic product assembly. Orthogonal experiments were used to study the compatibility of four different coated QFP devices, three kinds of plated PCBs, two temperature curves and SnPb solder paste, and the tensile strength of solder joints were measured. The solder joint morphology was analyzed by scanning electron microscopy. The results show that the solder joint strengths of Sn and SnPb coatings are higher than those of NiPdAu and SnBi coatings in the hybrid experiment of different coated devices. For pure Sn-coated devices, the lead temperature curve is compatible with the soldering of these devices. Three kinds of plating process used in the experiment, the leaded hot air leveling process on the best soldering temperature curve compatibility.