About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Electronic Packaging and Interconnection Materials III
|
| Presentation Title |
Enhancing Power Generation Stability of Thermoelectric Pillars by Suppressing Diffusion and IMC Formation at the Bi-Te/Sn Interface Using Co-P Coatings |
| Author(s) |
Fu Guo, Limin Ma, Shuang Liu |
| On-Site Speaker (Planned) |
Fu Guo |
| Abstract Scope |
Reliability of thermoelectric device packaging was critically affected by interfacial reactions and diffusion between solder and Bi-Te-based thermoelectric materials. Our work systematically investigated the microstructural evolution, failure mechanisms, and mitigation strategies at Bi-Sb-Te/Sn and Bi₂Te₃/Sn interfaces. Severe interdiffusion led to the formation of brittle intermetallic compounds (IMCs) such as SnTe, Bi₂Te, and Bi/Sb-rich phases, along with Kirkendall voids and microcracks, causing rapid degradation of mechanical and electrical performance. We demonstrated that introducing a crystalline Co-P coating as a diffusion barrier effectively suppressed Sn, Bi, Sb, and Cu migration, forming only an ultrathin CoTe₂ IMC layer (<100 nm). With Co-P protection, after 150℃ aging for 150 h, the maximum output power decay was reduced from 74% to 16% (p-type) and from 72% to 20% (n-type), and the increase in internal resistance was limited to 8%. These findings offer quantitative guidance for enhancing solder joint reliability and device longevity in advanced thermoelectric packaging. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Joining, Characterization, Copper / Nickel / Cobalt |