Synthesis and characterization of lead-free solders with Sn-3.5Ag-xCu (x=0.2, 0.5, 1.0) alloy nanoparticles by the chemical reduction method
Synthesis and characterization of lead-free solders with Sn-3.5Ag-xCu (x=0.2, 0.5, 1.0) alloy nanoparticles by the chemical reduction method
复制标题
DOI：
10.1149/1.1954928
复制
发表时间：
2005-01-01
影响因子：
3.9
通讯作者：
Duh, JG
中科院分区：
文献类型：
--
作者：
Hsiao, LY;Duh, JG
由于对人类健康和自然环境的担忧，有必要研究一种替代的无铅焊料。目前，近共晶SnAgCu合金作为无铅焊料正在被开发。在本研究中，采用NaBH4化学沉淀法合成了Sn-3.5 Ag-xCu （x = 0.2, 0.5, 1.0）纳米粒子的无铅焊料。x射线衍射（XRD）结果表明，Ag3Sn是在合金化过程中形成的。XRD分析表明，当Cu浓度达到1.0 wt %时，制备的纳米粉体只生成Cu6Sn5。Ag3Sn和Cu6Sn5的形成有力地证明了纳米颗粒是均匀混合的。通过透射电镜观察，分离颗粒接近球形，粉末粒径约为5 nm。SnAgCu纳米颗粒的场发射扫描电镜形貌表明，SnAgCu纳米颗粒的主要粒径在40 nm左右。差示扫描量热分析结果表明，SnAgCu纳米颗粒可以成功熔化。在润湿性试验中，回流后的钎料与基体之间表现出良好的冶金结合。因此，本研究通过化学还原法制得的纳米颗粒可以作为合适的电子封装焊料粉。(c) 2005电化学学会。
Due to the concerns of human health and the natural environment, the investigation of an alternative Pb-free solder is necessary. Currently, near-eutectic SnAgCu alloys are being developed as a lead-free solder. In this study, lead-free solders with Sn-3.5 Ag-xCu (x = 0.2, 0.5, 1.0) nanoparticles were synthesized by chemical precipitation with NaBH4. The X-ray diffraction (XRD) patterns revealed that the Ag3Sn was formed due to the alloying process. From the XRD patterns, only Cu6Sn5 was formed when Cu concentration was as high as 1.0 wt % in the derived nanopowders. The formation of Ag3Sn and Cu6Sn5 gave strong evidence that the nanoparticles were mixed homogeneously. From transmission electron microscopy observation, the isolated particles were close to spherical shape and the particle sizes of powders were about 5 nm. The field emission scanning electron microscopy morphology of SnAgCu nanoparticles indicates that the major particle size of SnAgCu nanoparticles is in the range of 40 nm. It was evidenced from the differential scanning calorimetry profile that the SnAgCu nanoparticles could be melted successfully. In the wettability test, good metallurgical bonding was revealed between solders and substrates after reflow. Thus, the nanoparticles derived by the chemical reduction method in this study can be used as appropriate solder powders in electronic packaging. (c) 2005 The Electrochemical Society.