无掩模定域性电沉积增材制造高深宽比三维金属微结构的关键技术研究

According to the requirements and development trend of micro-fabrication technology for MEMS micro parts and 3D microstructures, combining the characteristics of localized electrodepositing (LECD) and additive manufacturing (AM), a method of maskless LECD is proposed for additive manufacturing 3D metal microstructures with high precision, high aspect ratio and micro-nano crystalline structure. The main study contents of key technology are as follow: 1) Mass transfer characteristics and efficient control of mass transfer process of electrolyte within micro-electrodepositing region. 2) Characteristics, simulation, numerical solution and experimental verification of maskless LECD process for AM. 3) Controlling of uniformity current distribution within micro-electrodepositing region on cathodic surface and controlling of consistency current density within micro-electrodepositing region inter electrodes. 4) Controlling of invariance electrode spacing and current stability inter electrodes. 5) Controlling of narrowest line width and line width fluctuations of electrodepositing, and controlling of minimum layer thickness and layer thickness fluctuations of electrodepositing. 6) Controlling of thickness uniformity of electrodepositing layer and controlling of consistency of electrodepositing rate. 7) Controlling of dimensional accuracy and shape accuracy of 3D metal microstructure. Further improvement of kinetics mechanism and characteristics of electrode reaction within micro-electrodepositing region, the characteristics of current distribution within the inter-electrode gap micro-area, and the influencing law of main parameters on process and formation mechanism of crystal structure will be carried out, finally form a new micro-machining technology for manufacturing 3D metal microstructures and parts with high precision and high aspect ratio. The research results may provide theoretical and technical support for achieving the integration of "control shape/control performance" for electrodepositing-additive manufacturing 3D metal microstructures in the near future.

针对MEMS微小零件、三维微结构的微细加工需求与发展趋势，结合定域性电沉积与增材制造的技术特点，提出无掩模定域性电沉积增材制造方法制作成形精度高、具有微纳晶态组织的高深宽比三维金属微结构。主要开展如下的关键技术研究：1）微区域电解液传质特性及高效传质过程控制。2）无掩模定域性电沉积增材制造过程特征及其模拟仿真、数值求解与实验验证。3）阴极表面微区域电流分布均匀性与极间微区域电流密度一致性控制技术。4）极间间隙与电流稳定性控制技术。5）电沉积的最窄线宽与线宽波动量、最小层厚与层厚波动量的控制技术。6）沉积层厚度均匀性与沉积速率一致性控制技术。7）三维金属微结构尺寸精度与形状精度控制技术。通过项目研究进一步完善无掩模定域性电沉积微区域电极反应动力学机理及其特征，掌握极间间隙微区域电流分布特性、主要工艺参数对工艺过程的影响规律和沉积层晶态组织形成机制，形成高精度、高深宽比三维金属微结构与零件的微细加工新技术。研究成果可为今后实现三维金属微结构电沉积增材制造技术的“控形/控性”一体化提供理论与技术支持。

一、项目的背景.针对MEMS微小零件、三维微结构的微细加工需求与发展趋势，结合定域性电沉积与增材制造的技术特点，提出无掩模定域性电沉积增材制造方法制作成形精度高、具有微纳组织结构的高深宽比三维金属微结构。.二、主要研究内容.1、微区域电解液传质特性及高效传质过程控制。.2、无掩模定域性电沉积增材制造过程特征及其模拟仿真、数值求解与实验验证。.3、阴极表面微区域电流分布均匀性与极间微区域电流密度一致性控制。.4、极间间隙与电流稳定性控制。.5、电沉积的最窄线宽与线宽波动量、最小层厚与层厚波动量的控制。.6、沉积层厚度均匀性与沉积速率一致性控制。.7、三维微结构尺寸精度与形状精度控制。.8、主要工艺参数对工艺过程的影响规律。.三、重要结果.1、探索出的与电沉积工艺特征相适配的三维结构CAD模型建立与切片处理方法，可为相关电化学增材制造提供技术支持。.2、使用相关软件进行仿真模拟的结果及建立的相关数学模型，可为相关电化学增材制造提供理论方面的借鉴与参考。.3、研究的微区域高效传质过程、阴极表面电流分布均匀性、极间电流密度一致性及沉积速率一致性、线宽波动量与层厚波动量的控制技术等，具有实用性。.4、获得的优化参数、电沉积成形过程与规律、沉积层晶态组织形成机制、“控形控性”方法等，可为相关无掩模定域性电沉积三维微结构提供技术支持。.四、关键数据.关键数据如下：极间距10-40μm，正向脉冲电压3.8-4.4V，频率3-5kHz，占空比30%-50%；外加顺电场方向的磁场强度0.4T，横向超声波功率240W；负向脉冲电压2V，频率0.5KHz，占空比为60%，正负脉冲个数比值为5:1。尖锥状铂针阳极头部圆角半径≤15μm。.五、科学意义.研究成果可进一步完善无掩模定域性电沉积微区域电极反应动力学机理及其特征，为今后实现三维金属微结构电沉积增材制造技术的“控形/控性”一体化提供技术支持。