Yang Zhehan, Pan Yi, Zhao Hengyu, Yang Xiangmin, Liang Ying, Zhang Zhen, Fang Bin
Institute of Nuclear Technology and Application, School of Science, East China University of Science and Technology Shanghai 200237 P. R. China
RSC Adv. 2021 Aug 2;11(42):26408-26414. doi: 10.1039/d1ra02514g. eCollection 2021 Jul 27.
The rapid development of flexible wearable electronics arouses huge demand for low-temperature sintering metal inks applied to temperature-sensitive substrates. The high sintering temperature and easy oxidation limited the application of Cu-based pastes. A two-step method involving liquid co-reduction and heat ripening was developed to synthesize Cu@Sn-Bi core-shell particles. The thickness of Sn-Bi shells can be flexibly adjusted changing the mass ratio of Cu to Sn-Bi. The volume resistivity of printed circuits using Cu@Sn-Bi pastes solidified at 200 °C was as low as 481 μΩ cm, which increased by 11.8% after an aging process at 190 °C for 6 h. The outstanding stability in a harsh environment would attribute to the effective protection of Sn-Bi alloy shells. This work suggests a new pathway toward the low-temperature bonding and anti-oxidation of Cu particles as conductive fillers, which can be widely applied to the additive manufacturing of flexible wearable electronics.
柔性可穿戴电子设备的快速发展引发了对应用于温度敏感基板的低温烧结金属油墨的巨大需求。高烧结温度和易氧化限制了铜基浆料的应用。开发了一种包括液相共还原和热熟化的两步法来合成Cu@Sn-Bi核壳颗粒。通过改变Cu与Sn-Bi的质量比，可以灵活调整Sn-Bi壳的厚度。使用在200℃固化的Cu@Sn-Bi浆料印刷的电路的体积电阻率低至481μΩ·cm，在190℃老化6小时后增加了11.8%。在恶劣环境中的出色稳定性归因于Sn-Bi合金壳的有效保护。这项工作为作为导电填料的铜颗粒的低温键合和抗氧化提供了一条新途径，可广泛应用于柔性可穿戴电子设备的增材制造。
