Thermofluidic Transport in Printing and Laser Curing of Nanoparticle Solutions

摘要该研究项目研究了一种新的工艺，用于低温印刷和固化薄金线，使用纳米颗粒浆料微沉积（印刷）和激光加热（固化）。这种混合微印刷和激光固化方法将用于制造电子电路中的导体。主要的物理现象包括纳米颗粒在激光辐射的影响下在液体载体蒸发的存在下熔化和键合。该过程由印刷液滴在基底上的扩散和毛细流动的动态演变介导。将开发一种方法用于在柔性聚合物基板上写入高电导率微线。将实施在线诊断，以监测和优化工艺的动态演变。对液滴扩散过程中的热物理传输、溶剂蒸发过程和纳米粒子键合过程进行了理论分析和数值计算。纳米粒子的键合机制将通过时间分辨近场光学扫描显微镜（NSOM）实验诊断进行研究，该研究将为利用纳米粒子材料独特的热物理性质的一系列新技术奠定科学基础。通过一系列新的实验和详细的计算，我们将了解微印刷中复杂的热流体传输现象、纳米颗粒悬浮液的激光辅助固化和纳米颗粒键合过程。该项目开发的技术将用于在柔性基板上构建电子互连，包括平板显示器、交叉导体、电容器和天线的制造。通过应用高度局部化的脉冲激光辐射，将实现用于功能微部件制造的精细特征。直接写入三维导电微结构，以及利用这种技术的快速原型和微加工工艺将继续进行。研究结果将被纳入课程作业，正式研讨会和研讨会。这项研究由化学和运输过程部门的热运输和热处理计划以及设计，制造和工业创新部门的纳米制造计划共同资助。

AbstractThe research project investigates a new process for the low-temperature printing and curing of thin gold lines, using nanoparticle slurry microdeposition (printing) and laser heating (curing). This hybrid microprinting and laser curing method will be used for the fabrication of conductors in electronic circuits. The main physical phenomena involve nanoparticle melting and bonding in the presence of the liquid carrier evaporation under the influence of laser radiation. The process is mediated by the spreading of the printed droplets on the substrate and by the dynamic evolution of the capillary flow. A methodology will be developed for writing high electrical conductivity microlines on flexible polymer substrates. On-line diagnostics will be implemented for monitoring and optimizing the dynamic evolution of the process. Theoretical analysis and numerical computations of the thermophysical transport in the droplet spreading, of the solvent evaporation and nanoparticle bonding will be conducted. The mechanics of the nanoparticle bonding will be investigated by time-resolved, near-field-optical scanning microscopy (NSOM) experimental diagnostics.The research will establish the scientific basis for a host of novel technologies utilizing the unique thermophysical properties of nanoparticle materials. Specifically, the complex thermofluidic transport phenomena in the microprinting, the laser-assisted curing of nanoparticle suspensions and nanoparticle bonding processes will be understood via an array of new experiments coupled with detailed computations.The technology developed in this project will be utilized to build interconnections in electronics on flexible substrates, including the manufacture of flat panel displays, crossover conductors, capacitors and antennae. Fine features for the fabrication of functional micro-components will be achieved by applying highly localized and pulsed laser radiation. The direct writing of three-dimensional conducting microstructures, as well as rapid prototyping and microfabrication processes that take advantage of this technology will be pursued. The research findings will be incorporated into coursework, a formal seminar and a workshop.This research has been jointly funded by the Thermal Transport and Thermal Processing Program of the Division of Chemical and Transport Processes and the Nanomanufacturing Program of the Division of Design, Manufacturing and Industrial Innovation.