Preparation Of Cu₆Sn₅ Nanoparticles And Exploration Of Joining Process Of Cu₆Sn₅

Cu6Sn5 is a common Cu-Sn intermetallic compound, in the traditional role of the Sn-based solder, it is easy to form at the interface, but because mutual diffusion will produce Kirkendall voids between the Cu-Sn,this will cause solder performance degradation of joining point. This article explores the ambient temperature and pressure, pure Cu and Sn and Cu6Sn5 nanoparticles were prepared by chemical reactions. Initial exploration of its implementation in the micro-welding process for connecting field has been done, the solder joints mechanical properties, wettability, weld and solder microstructure changes and how IMC is generated at the interface was investigatedFirst, Cu, Sn, Cu6Sn5 was prepared by redox reaction. Oxidant were used oxidizing agent is Cu Cl2?2H2O and Sn Cl2?2H2O, reducing the use of Na BH4, PVP is used as dispersant. During the experiment, ethanol is used as a solvent, and the use of mixed proportional manner prepared experiment found that, concentration of Sn Cl2 ethanol Cu Cl2 ethanol were 0..020 g / ml of, 0.008 g / ml, 0.016 g / ml PVP ethanol solution g / ml, and the excess of Na BH4 suspension were mixed in equal volumes to give pure elemental Cu, Sn simple substance, as well as the Cu6Sn5 intermetallic compound can be prepared. Wherein the average particle size was as 50.45 nm, 84.73 nm, and 47.46 nm. Purities of Cu6Sn5 can be changed by concentration of the solution and the concentration of PVP solution. Changes of both the 2 experimental parameters could bring Cu6Sn5, whose contaminants typically Cu2 O or Sn O2Then in the process of joining, the weldability, mechanical properties of Cu6Sn5 solder, and microstructure at the interface of Sn doped with IMC was investigated. Very close solder wetting angle decreases with increasing temperature, the experiment wetting properties is preferably 400 ℃. Mechanical Analysis found that changes solder joint strength and plasticity was the same trends, are positively associated with holding time and soldering temperature was. Then find the best value appearance, solder at 200 ℃ in a metallurgical bond is not formed at the interface. At 250 ℃ began local connection. And weld composition are Cu6Sn5, welded at the interface appeared Cu3 Sn, and with the increase in the holding time tended to increase.