电流密度对微/纳结构电铸成型模芯质量的影响

Effect of Current Density on Quality of Electroformed Mold Inserts with Micro/Nano-cavities

利用多物理场耦合分析软件COMSOL Multiphysics,模拟微/纳结构电铸过程中阴极表面的电场分布,研究不同电流密度下微/纳结构表面的电场分布及电铸层生长前沿情况。仿真结果表明:采用较低的初始电流密度,可有效改善微/纳结构生长前沿铸层厚度的均匀性。选用纳米光阑和纳米柱阵列2种微/纳结构母板进行电铸实验,将初始电流密度从4A/dm2调至1A/dm2,纳米光阑母板成型最大误差60nm降至±20nm之内。通过合理设置初始电流密度、增强阴极表面溶液流动强度等措施,纳米柱阵列模芯特征直径尺寸误差由6.27%下降至2.49%,有效提高电铸模芯的复制质量。

Based on the COMSOL Multiphysics software,the electric field distribution and the growth front of electroformed layer on the cathode surface were simulated during the electroforming process.The simulation results show that the uniformity of electroformed layer with micro/nano-cavities can be effectively improved with a better replication quality by using a lower initial current density.Both nano-diaphragm and nanopillar array are selected as masters for the electroforming experiments.When the initial current density decreases from 4 A/dm2 to 1 A/dm2,the maximum deviation of characteristic width between the nano-diaphragm master and mold inserts dramatically decreases from 60 nm to±20 nm.By setting proper current density and enhancing mass transfer near the cathode surface,the characteristic diameter dimension error of electroformed mold inserts for nanopillar array decreases from 6.27%to 2.49%.The replication quality of electroformed mold inserts with micro/nano-cavities can be significantly improved by these methods.