Skwarek Agata, Choi Halim, Hurtony Tamás, Byun Jaeduk, Mohamad Ahmad Azmin, Bušek David, Dušek Karel, Illés Balázs
Łukasiewicz Research Network, Institute of Microelectronics and Photonics, 30-701 Kraków, Poland.
Department of Electronics Technology, Faculty of Electrical Engineering and Informatics, Budapest University of Technology and Economics, 1111 Budapest, Hungary.
Nanomaterials (Basel). 2024 Oct 12;14(20):1636. doi: 10.3390/nano14201636.
This study investigates the mechanism and effects of incorporating different ZrO nano-particles into SAC0307 solder alloys. ZrO nano-powder and nano-fibers in 0.25-0.5 wt% were added to the SAC0307 alloy to prepare composite solder joints by surface mount technology. The solder joints were shear tested before and after a 4000 h long 85 °C/85% RH corrosive reliability test. The incorporation of ZrO nano-particles enhanced the initial shear force of the solder joint, but they decreased the corrosion resistance in the case of 0.5 wt%. SEM, EDS, and FIB analysis revealed intensive growth of SnO on the solder joint surfaces, leading to the formation of Sn whiskers. Density functional theory (DFT) simulations showed that, despite Sn being able to bond to the surface of ZrO, the binding energy was weak, and the whole system was therefore unstable. It was also found that ZrO nano-particles refined the microstructure of the solder joints. Decreased β-Sn grain size and more dispersed intermetallic compounds were observed. The microstructural refinement caused mechanical improvement of the ZrO composite solder joints by dispersion strengthening but could also decrease their corrosion resistance. While ZrO nano-particles improved the solder joint mechanical properties, their use is recommended only in non-corrosive environments, such as microelectronics for space applications.
本研究调查了将不同的ZrO纳米颗粒掺入SAC0307焊料合金中的机制和效果。将0.25 - 0.5 wt%的ZrO纳米粉末和纳米纤维添加到SAC0307合金中，通过表面贴装技术制备复合焊点。在进行4000小时的85°C/85%RH腐蚀可靠性测试前后，对焊点进行剪切测试。掺入ZrO纳米颗粒提高了焊点的初始剪切力，但在0.5 wt%的情况下降低了耐腐蚀性。扫描电子显微镜（SEM）、能谱分析（EDS）和聚焦离子束（FIB）分析表明，焊点表面有大量SnO生长，导致形成锡须。密度泛函理论（DFT）模拟表明，尽管Sn能够与ZrO表面结合，但结合能较弱，因此整个系统不稳定。还发现ZrO纳米颗粒细化了焊点的微观结构。观察到β-Sn晶粒尺寸减小，金属间化合物更加分散。微观结构的细化通过弥散强化提高了ZrO复合焊点的力学性能，但也可能降低其耐腐蚀性。虽然ZrO纳米颗粒改善了焊点的力学性能，但仅建议在非腐蚀性环境中使用，如空间应用的微电子领域。
