Li Lihua, Zhou Jian
Sino-German College of Intelligent Manufacturing, Shenzhen Technology University, Shenzhen 518118, China.
School of Mechanical Engineering, Hefei University of Technology, Hefei 230009, China.
Nanomaterials (Basel). 2021 Feb 1;11(2):363. doi: 10.3390/nano11020363.
A newly developed hot embossing technique which uses the localized rapid heating of a thin carbide-bonded graphene (CBG) coating, greatly reduces the energy consumption and promotes the fabrication efficiency. However, because of the non-isothermal heat transfer process, significant geometric deviation and residual stress could be introduced. In this paper, we successfully facilitate the CBG-heating-based hot embossing into the fabrication of microlens array on inorganic glass N-BK7 substrate, where the forming temperature is as high as 800 °C. The embossed microlens array has high replication fidelity, but an obvious geometric warpage along the glass substrate also arises. Thermo-mechanical coupled finite element modelling of the embossing process is conducted and verified by the experimental results. Based on trial and error simulations, an appropriate compensation curvature is determined and adopted to modify the geometrical design of the silicon wafer mold. The warpage of the re-embossed microlens array is significantly decreased using the compensated mold, which demonstrates the feasibility of the simulation-oriented compensation scheme. Our work would contribute to improving the quality of optics embossed by this innovative CBG-heating-based hot embossing technique.
一种新开发的热压印技术，该技术利用对薄的碳化物键合石墨烯（CBG）涂层进行局部快速加热，大大降低了能耗并提高了制造效率。然而，由于非等温传热过程，可能会引入显著的几何偏差和残余应力。在本文中，我们成功地将基于CBG加热的热压印应用于在无机玻璃N-BK7基板上制造微透镜阵列，其成型温度高达800°C。压印的微透镜阵列具有高复制保真度，但沿玻璃基板也出现了明显的几何翘曲。对压印过程进行了热-机械耦合有限元建模，并通过实验结果进行了验证。基于反复试验模拟，确定并采用了合适的补偿曲率来修改硅片模具的几何设计。使用补偿模具后，重新压印的微透镜阵列的翘曲显著降低，这证明了面向模拟的补偿方案的可行性。我们的工作将有助于提高通过这种基于CBG加热的创新热压印技术压印的光学器件的质量。
