Reflow behavior of a Sn-8.5Zn-0.5Ag-0.01Al-0.1Ga (five-element) solder on the Ni/Cu substrate was investigated under different heating rates. Reflowed samples show decreased Zn and increased AgZn3 in the solder with a reduction in the heating rate. The Zn at the solder/substrate interface was found to be much lower than that in the Sn-Zn solder systems. Cu was observed to be diffused through the electroplated Ni layer and noticed only with the Ag-Zn compound in the solder. Ga was spotted at the interface in the Ag-Zn matrix, whereas Al was detected with the Zn at the interface. Small intermetallic compound (IMC) layer was formed at the interface; however, its amount enhanced with the reduction in the heating rate. Present study relates the reflow behavior of the five-element solder with the reactivity of different elements in the system and its influence on the formation of IMCs in the solder and at the solder/substrate interface.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Mechanical Engineering
- Mechanics of Materials
- Condensed Matter Physics