Recent environmental and health concerns regarding the toxicity of lead have facilitated the development of lead-free solder alloys with suitable soldering characteristics and mechanical properties. Compared to the lead-containing solders, however, the lead-free solders are stiffer and less deformable during dynamic loading. In the present study, the shear and pull ball tests were employed to evaluate the impact strength of solder ball attachments. Tests were conducted on as-reflowed and aged Ni-doped and non-Ni-doped Sn-Cu solder ball grid arrays (BGAs) placed on Cu substrates over a wide range of displacement rates. Trace Ni addition to the Sn-Cu solders prevented the growth of the interface intermetallic compounds (IMCs) and made the IMC layer morphology smooth. As-reflowed Sn-Cu-Ni BGA joints show superior properties in high speed shear and pull impact tests.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
- General Materials Science