电场诱导微结构图形化形成机理及常温制备工艺

Room-Temperature Electrically Induced Micro-Structure Patterning Mechanism and Technique

利用液体薄膜表面热扰动造成的表面张力失稳特性,提出一种常温条件下的非接触式电场诱导聚合物图形化技术.采用Navier-Stokes方程和线性稳定分析理论建立了薄膜流体的电场诱导力学模型,阐明了电场诱导过程中微结构的形成机理和周期特性,并详细分析了微结构的成长因数.采用低黏度紫外光固化型聚合物作为图形化材料,在常温条件进行了电场诱导成形实验研究,实验结果证明了电场诱导成形在常温条件下应用于紫外光固化型聚合物的可行性.在导电的掺杂硅片基底上以匀胶方式制备0.8μm厚的紫外光固化型聚合物薄膜,使用平整的导电玻璃作为无图形模板.在基底和模板间施加25 V的直流电压进行电场诱导成形实验,获得了平均中心间距为37.6μm,平均直径为24.8μm的大面积周期性柱状结构.将基底和模板间的电压提高至30 V,周期性柱状结构的中心间距降低为30.8μm,平均直径降低为18.5μm.另外,采用理论模型对诱导成形过程中的诱导时间、成形特点和图型特征等要素进行了详细的分析,并提出了获得高精度、快速电场诱导图形化的工艺参数优化方案.

A non-contact electrically induced patterning technique was proposed for forming a periodic micro-structure on a polymer film at room temperature,based on the surface tension instability of liquid polymer film caused by thermal disturbance.An electro-mechanical model for the electrically induced polymer film rheology was established by using the Navier-Stokes equation and a linear stability theory to analyze the patterning dynamics,periodicity and growth factor of the micro-structure generated by the electrical field.An experiment of the electrically induced micro-patterning process at room temperature was carried out by using a low-viscosity UV curable polymer as the material for patterning.The experimental results have validated the feasibility of the electrically induced patterning with UV curable polymer at room temperature.The UV curable polymer film with a thickness of 0.8 μm was coated on the substrate of conductive doped silicon wafer and smooth conductive glass was used as flat mask.Direct current with voltage of 25 V was applied between the substrate and mask to carry out the experiment of electrically induced patterning,in which periodic pillars on large area were obtained,with the average centre to centre spacing of 37.6 μm and the average diameter of 24.8 μm.When the applied voltage was raised to 30 V,the average centre to centre spacing of periodic pillars was reduced to 30.8 μm and the average diameter of periodic pillars was reduced to 18.5 μm.Factors in the electrically induced process such as the induction time,template-to-film gap,and pattern size were analyzed in detail based on the theoretical model proposed.An approach to the process parameter optimization was suggested for achieving quick and high precision electrically induced patterning.