| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 545108 | Microelectronics Reliability | 2010 | 8 Pages |
Nano-sized, nonreacting, noncoarsening Al2O3 particles have been incorporated into eutectic Sn–Zn solder alloys to investigate the microstructure, hardness and shear strength on Au/Ni metallized Cu pads ball grid array substrate (BGA). In the plain Sn–Zn solder joint and solder joints containing Al2O3 nano-particles, a scallop-shaped AuZn3 intermetallic compound layer was found at the interfaces. In the solder joints containing Al2O3 nano-particles, a fine acicular-shaped Zn-rich phase and Al2O3 nano-particles were found to be homogeneously distributed in the β-Sn matrix. The shear strengths and hardness of solder joints containing higher percentage of Al2O3 nano-particles exhibited consistently higher value than those of plain solder joint and solder joints containing lower percentage of Al2O3 nano-particles due to control the fine microstructure as well as homogeneous distribution of Al2O3 nano-particles acting as a second phase dispersion strengthening mechanism. The fracture surfaces of plain Sn–Zn solder joints exhibited a brittle fracture mode with smooth surfaces while Sn–Zn solder joints containing Al2O3 nano-particles showed a typical ductile failure with very rough dimpled surfaces.
