金属微结构电铸成型的流场性能研究

Research on Flow Field Character of Micro Electroforming of Metallic Microstructure

为改善高深宽比金属微结构的电铸成型质量,在分析微细电铸的流场特性的基础上,深入研究了铸层厚度的不均匀现象及搅拌方式、流场分布对微细电铸的影响。由于高深宽比胶膜的存在,单一搅拌对电铸区域的影响只集中在微区的入口部分。扩散过程成为金属沉积的限制性因素;随着胶膜深宽比的增大,搅拌速度对电铸传质过程影响减小,导致电铸微区内金属离子传输能力不均匀。实验表明,微细电铸过程中,搅拌速度提高并不能改善金属沉积的传质条件;辅助超声的复合搅拌在相同条件下能提高金属沉积速度、减少铸层缺陷、改善传质。实现了高分辨率,侧壁陡直的金属微结构的电铸成型。

To improve the micro electroforming quality of the microstructure with large high aspect ratio,the characteristics of the micro electroforming process and the property of the flow field were analyzed and discussed systematically.The asymmetry phenomena of the deposit and the effect of the stirring mode,flow field on the microstructure were studied in detail.Experiment showed that the effect of the pure stirring concentrated on the entrance of the micro groove only.Diffusion was the control factors of micro electroforming process.The effect influencing on the mass transferring reduced with the increasing high aspect ratio of the deposit,which resulting in the discrepancy of ion transferring capacity in the reaction area.The results also showed that the stirring velocity could not improve transferring condition,while complex stirring with auxiliary ultrasonic could help to increase the deposit velocity and get the perfect microstructure.Based on the research on the flow field,high resolute electroforming microstructure with vertical wall was fabricated.