| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advanced Microelectronic Packaging, Emerging Interconnection Technology and Pb-free Solder
|
| Presentation Title |
Effects of Secondary Reflow on Solder Joint Microstructure and Lifetime |
| Author(s) |
Alyssa N. Yaeger, Travis Dale, Ganesh Subbarayan, John Blendell, Carol Handwerker |
| On-Site Speaker (Planned) |
Alyssa N. Yaeger |
| Abstract Scope |
Electroless Nickel Immersion Gold (ENIG) coatings are common in electronics for pads on circuit boards and surface mounted components. The Au in these coatings diffuses easily into SnPb solder during reflow and can form brittle intermetallics. With aging, these intermetallics coarsen and migrate to the Ni3Sn4 interface to form an additional intermetallic layer. Due to the diffusion of Ni into the intermetallic, a porous phosphorous-rich Ni-P layer forms between the electroless Ni coating and the intermetallic layer. Brittle fracture along the P-rich layer occurs in aged SnPb solder joints containing as little as 1wt% Au with ENIG coatings. The effects of secondary reflow as a form of mitigation for this brittle fracture will be discussed, with a focus on microstructural evolution and mechanical properties. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |