Geometrical Effects of Cu@Ag Core–Shell Nanoparticles Treated Flux on the Growth Behaviour of Intermetallics in Sn/Cu Solder Joints

摘要: Solder ball of initial diameter 1.4 mm, was reflow soldered with Cu substrate at 523.15 K using flux doped Cu@Ag core–shell nanoparticles (NPs) in the proportion 0–2 wt%. The solders were then air cooled to room temperature. use NPs, by reducing base height (H) solder and enhanced (W) solder, caused an overall increase spread ratio solder. altered magnitudes heat mass transfer these geometrically different but constant volume specimens analyzed finite element method. occurrence differential concentration gradient, radial thermal gradient velocity magnitudes, differing geometry numerically elaborated. $$\hbox {Cu}_{6}\hbox {Sn}_{5}$$ intermetallic compound (IMC) formed Cu/Sn interface, obtained be thickest for specimen undoped flux, whereas it found smallest sample processed containing 0.5% NPs. From growth kinetics study, has been inferred that IMC thickness is linearly proportional geometrical parameter H {W}^b$$ , b < 1.