线阳极近接触扫描式掩膜电沉积加工技术

Through-mask electrodeposition is the mainstream technique for manufacturing high-end or special metallic structures and components with multiple-scales on a large run. Relatively small thickness distribution uniformity and much more defects appearing in the electroforms are the troublesome problems in the electrodeposition field that have not been solved yet. The main cause for that is: uniformization of the cathodic current distribution in the multiple-scale deposition zones is extremely hard to be achieved. Therefore, in order to enable the multiple-scale deposition zones to have uniform mass transfer and current distribution, this program specially proposes a solution which divides the macro-scale current into micro-volume current to supply to the deposition zones discretely and further develops a novel through-mask electrodeposition technique––wire anode scanning through-mask electrodeposition. This program focuses on investigating into the issues including the achievability and controllability of laminar-flow-state convective mass transfer on the surface of the resist patterns under the agitation with reciprocating paddle, characteristics of current distribution and deposition behaviors and their control mechanisms, as well as possible equations involving these issues. This program also puts its emphasis on the research on how to simulate the multiple-scale electrodeposition processes with a moving local micro-volume current and how to effectively and efficiently collect the important information charactering the current and mass transfer distribution within the confined micro-cavities. It is expected that the systematic theories of this newly proposed technique could be finally formed after above the issues and technologies problems are solved. A more advanced and more practicable through-mask electrodeposition is expected to be developed and further be served the fields of information technology, panel display and artificial intellectual, etc.

掩膜电沉积是规模化制造高端或特殊多尺度金属结构特征与零件的主流技术。厚度一致性偏低、沉积缺陷常现至今仍是其难解之题。症结是：难以克服面积/多尺度效应实现阴极电流均布化。对此，项目提出了实施方式奇特的线阳极近接触扫描式掩膜电沉积技术，以借助载有超微线状阳极的特殊形态电绝缘搅拌桨贴近胶膜表面的往复运动，来促成局域均匀传质场的随动构建和电流供给的时空离散化、微量化和按需化，进而达成传质-电流分布协同均衡化。重点研究胶膜表面层流态对流传质的实现与调控机制、图形化阴极电流分布/沉积行为特性及它们的调控机制等理论问题，建立机制/特性/行为表征数学表达式；着力突破移动态局域能场作用下多尺度沉积过程流场-电场耦合数值仿真、限域微区传质/电场特征信号获取等关键技术，理论研究与关键技术突破相协同，构建扫描式掩膜电沉积基础与技术体系，以期为IT、平板显示、人工智能等高技术领域产品的制造提供更先进适用的电沉积技术

掩膜电沉积是批量化并行制造精密微细金属构件的主流技术。厚度一致性偏低、沉积缺陷常现至今仍是其难解之题。其中的根本原因是：覆盖有电绝缘图案的阴极各处的电流密度和液相传质效率大小不一。对此，本项目提出了线阳极近阴极扫描掩膜电沉积新技术，通过载运有直线状超微阳极的机械搅拌桨贴近阴极作往复扫描运动以使电铸过程的赋能定向化、周期化和均等化，以实现宏-介-微跨尺度金属结构与零件的高厚度一致性、高质量批量化电铸。本项目的主要研究进展与贡献为：(1) 建立了线域电场作用下阴极过电势的分布函数，探明了阴极过电势分布特征与扫描速度间的映射关系；(2) 探明了线阳极近阴极扫描电沉积的工艺本质特征：以极高的局域阴极过电势（电流密度超500A/dm2）均等化赋能电沉积过程，建立了电沉积金属晶粒与扫描速度间的映射关系()，制备出晶粒极细（≤20nm）、超纯（99.9997%）、超光滑表面（Ra≤20nm）且兼具高硬度（600~650HV）、高韧性（断裂最大伸长率高达8.5%）的综合机械性能优异的镍薄膜材料；(3) 建立了流-电耦合物理和数学模型，研究了电沉积过程流场、电场分布特征及其时空演化规律，探明了线阳极近阴极扫描电沉积制件高成形精度、高厚度一致性的支撑理论本质；(4) 研制出线阳极近阴极扫描电沉积中试装备，系统开展了工艺优化实验研究，批量化并行电铸出多种高厚度一致性（尺寸偏差≤5.84μm/100μm）金属微细构件；(5) 证实了线阳极近阴极扫描电沉积PCB和IC铜互连微细结构的技术优势：电学性能更优，沉积缺陷更少；(6) 基于线阳极扫描电沉积原理提出了金属功能表面制备新策略，制备出致密层与粗糙层交替的、机械耐久性优异的集水集雾镍表面。. 发表论文13篇，授权专利15项，培养青年学术骨干1名、硕/博士研究生6名，获省部级科技二等奖3项。研究成果丰富与发展了掩膜电沉积基础理论，并用于ICU（重症监护室）Pd-Ni合金超声雾化片、医用清创水刀喷嘴、超窄光学狭缝片等产品的研制与生产，实现进口替代。