铜纳米颗粒的飞秒激光连接过程研究  

Joining Process of Copper Nanoparticles with Femtosecond Laser Irradiation

作　　者：廖嘉宁 王欣达 周兴汶 康慧[1] 郭伟[1] 彭鹏[1] Liao Jianing;Wang Xinda;Zhou Xingwen;Kang Hui;Guo Wei;Peng Peng(School of Mechanical Engineering&Automation,Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学机械工程及自动化学院,北京100191

出　　处：《中国激光》2021年第8期86-93,共8页Chinese Journal of Lasers

基　　金：国家重点研发计划(2017YFB1104900);国家自然科学基金(51975033);北京市自然科学基金(3192020)。

摘　　要：采用飞秒激光对铜离子前驱体薄膜进行激光直写,原位还原得到铜纳米颗粒并连接形成导电铜微结构。实验研究了激光功率对铜微结构物相成分、微观结构及导电性能的影响。进一步,利用COMSOL仿真软件模拟了飞秒激光辐照下铜纳米颗粒二聚体的电场分布及温度场分布特征,计算了不同功率单脉冲激光对铜纳米颗粒电子温度及晶格温度的影响。仿真结果表明,激光诱导表面等离激元效应可实现对纳米颗粒的局域加热。当激光功率为960 mW时,纳米颗粒热点区域的晶格温度最高为698 K,纳米颗粒出现表面熔化现象,可实现颗粒间的连接。随着入射激光功率的升高,晶格温度升高,颗粒间连接程度提高,与实验结果相一致。Objective Copper(Cu)nanoparticle exhibits high potential as an interconnecting material in electronic devices due to its relatively lower cost and similar conductivity compared with other noble metals.The interconnection between Cu nanoparticles can optimize the electrical conductivity and optical and mechanical properties of fabricated Cu microstructures.Compared with other traditional joining technologies,laser-induced nanojoining has the advantages of high precision,low damage,and high efficiency.In particular,femtosecond lasers with high peak power and ultrashort pulse duration would limit the heat-affected zone and result in less damage of joint than other lasers with longer pulse duration or continuous wave.When femtosecond laser pulse interacts with metallic nanomaterials,electrons absorb photons and quickly reach a higher temperature,while the lattice remains unchanged,resulting in less thermal effect and local melting during processing.It is expected to have potential in joining materials at nanoscale.At present,some reports focus on the reduction of Cu nanoparticles by femtosecond laser irradiation,whereas the effect of femtosecond laser on the joining process of Cu nanoparticles is yet to be understood.The joining mechanism and laser thermal effect on the joining of Cu nanoparticles need to be given more effort to optimize the femtosecond laser processing.In this work,femtosecond laser direct-writing is used to in-situ reduce Cu nanoparticles and join them to form a conductive copper microstructure.The effect of laser power on the composition,microstructure,and conductivity of Cu microstructures are investigated.Furthermore,the effect of single-shot laser pulses on the electron and lattice temperature in the“hotspot”between a Cu nanoparticle dimer is calculated.Simulation experimental results are compared to understand the joining process and mechanism of Cu nanoparticles under femtosecond laser irradiation.Methods In a typical experimental procedure,the aqueous solution of polymethacrylic acid sod

关 键 词：激光技术 飞秒激光 铜纳米颗粒 纳米连接 界面 局域温度 

分 类 号：TN249[电子电信—物理电子学]