Electrochemical migration (ECM) characteristic is a new reliability failure. A parallel surfacial electrode system coupling with scanning electron microscope (SEM), energy dispersive X-ray analysis (EDAX), and X-ray Diffraction (XRD) technologies is designed to research ECM behavior of 64Sn-35Bi-1Ag (SBA) solder in 3.5 g/L NaCl solution and compare to that of Sn37Pb and Sn-3.0Ag-0.5Cu (SAC) solders. Results show that SBA solder is more susceptible to ECM failure than Sn37Pb solder, which is more difficult than SAC solder. The affected factors of ECM are given as follows: the solder compositions, the loaded electric field, ECM time, etc. The electrochemical reaction mechanism of ECM process is achieved. EDAX and XRD analyses show that the main contents on dendrites of SBA solder after ECM test are Sn, hardly any Bi, a little Ag, which illustrates that the order of ion migration capacity is shown as follows: Sn Ag Bi.
With development of miniaturization,high integration,multifunction and high efficiency of electronic packaging technology,a higher requirement for soldering material and its enlistment property is needed.It is easily subjected to reliability failure for electronic products or components packaged with micro/nanoelectronic packaging technology.In this paper,research process and some typical failure mechanisms on interconnect solder point reliability are discussed,including electro-migration (EM),thermal migration (TM),K-cavity,corrosion,electrochemical migration (ECM) and whisker growth,etc.It provides the basic data for the new generation of micro/nano-packaging technique to improve the fine-pitch jointing reliability.
以单分散法制备的聚甲基丙烯酸甲酯(PMMA)微球为模板,合成三维多孔(3DOM)LiMnPO_4锂电池正极材料,制备的材料为橄榄石型结构。N_2吸附-脱附分析显示,3DOM LiMnPO_4比表面积较大,为34.63 m^2/g。电化学性能测试表明,首次比容量接近于120 m A·h/g,循环充放电60次时仍保持较好的稳定性。模板法获得的LiMnPO_4呈多孔结构,有利于降低离子或电荷迁移到电解液或电极表面的阻力,从而降低了电极表面的极化,有利于锂离子脱嵌,进而提高充放电的循环稳定性。
