Origin of Primary Cu6Sn5 in Hypoeutectic Solder Alloys and a Method of Suppression to Improve Mechanical Properties
| Autor: | Flora Somidin, Kazuhiro Nogita, Hideyuki Yasuda, Z. Shayfull, Mohd Izrul Izwan Ramli, Jitrin Chaiprapa, S. F. N. Muhd Amli, Mohd Arif Anuar Mohd Salleh |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Materials science Metallurgy Alloy Electroless nickel immersion gold chemistry.chemical_element 02 engineering and technology engineering.material 021001 nanoscience & nanotechnology Condensed Matter Physics Microstructure 01 natural sciences Copper Electronic Optical and Magnetic Materials chemistry Organic solderability preservative Soldering 0103 physical sciences Materials Chemistry engineering Electrical and Electronic Engineering 0210 nano-technology Dissolution Eutectic system |
| Zdroj: | Journal of Electronic Materials. 50:710-722 |
| ISSN: | 1543-186X 0361-5235 |
| DOI: | 10.1007/s11664-020-08428-9 |
| Popis: | This study examines factor(s) behind the formation of primary Cu6Sn5 (in the bulk, rather than at the interface) in solder joints, even though solder alloys are hypoeutectic. To understand the contribution from copper (Cu) dissolution from the substrate a Cu-free alloy, tin-3.5 silver (Sn-3.5Ag), was used as a soldered-on copper organic solderability preservative (Cu-OSP) and electroless nickel immersion gold (ENIG) surface finish substrates. Microstructure observations including in situ synchrotron were used to observe microstructure development real-time and confirm the time and location for nucleation of primary Cu6Sn5. High-speed shear tests were performed to determine the solder joint’s strengths. The results confirm that Cu dissolution during soldering is responsible for the formation of primary Cu6Sn5. The ENIG finish prevented Cu dissolution and the formation of Cu6Sn5 resulting in higher solder joint strength for the Sn-3.5Ag/ENIG solder joints. The findings can be used to understand the evolution of primary Cu6Sn5 and how it can be suppressed to improve joint strength. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink