Ultra Precision 3D Micromachining

超精密 3D 微加工

• 批准号: 0423315
• 负责人: Thomas Dow
• 金额: $ 10万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-15 至 2007-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0423315&HistoricalAwards=false
• 关键词: Ultra; Precision; 3D; Micromachining

This project will demonstrate the effectiveness of a new micromachining process that can be used to create three-dimensional micro-mechanical, micro-optical and micro-fluidic devices in a wide variety of materials. Current micromilling techniques using high-speed spindles are plagued by spindle and tool runout that limit the feature size and tolerance. The concept is to replace the high-speed spindle with a piezoelectric driven tool holder that can move the diamond tool tip in a planar motion at frequencies up to 5000 Hz - the equivalent of 300,000 rpm. The two linear actuators are driven out of phase to create a tool path that can be changed from linear to elliptical to circular by varying the amplitude, frequency and phase of the excitation voltages. The goal is to significantly improve the capability of the mechanical machining by pushing the minimum feature size from 25 um to 1 um and the feature tolerance from 2 um to less than 200 nm while producing optical quality surface finish in a variety of materials. Microelectromechanical systems (MEMS) offer designers the ability to create miniature mechanical oscillators, optical network components and biological labs on a chip, but the high cost and long lead time needed to create such devices using commercial semiconductor fabrication facilities has been an impediment to their widespread acceptance. Semiconductor techniques are designed for high-volume circuits using standard CMOS processing while many MEMS devices are needed in lower volumes, have more complex structures (such as moving three-dimensional micromirrors arrays) and require materials other than silicon. Past MEMS machining research has emphasized high-speed spindles while the effort introduces a new technique that avoids the runout issues inherent with a rotating spindle allowing smaller, more accurate features to be created. The resulting chip geometry leads to reduced machining forces and reduced tool/workpiece contact time creating longer tool life and extending the range of workpiece materials (plastics, metals and ceramics) when compared to normal diamond turning. The experiments are designed to study the material flow at small depths of cut, to define the limits of the process and to identify the optimum cutting conditions for different workpiece materials. Fabrication of prototype devices will demonstrate the integration of mechanical, optical and fluidic structures in 3D.

该项目将展示一种新的微加工工艺的有效性，该工艺可用于用多种材料制造三维微机械、微光学和微流体装置。 当前使用高速主轴的微铣削技术受到主轴和刀具跳动的困扰，从而限制了特征尺寸和公差。 其概念是用压电驱动刀架取代高速主轴，压电驱动刀架可以以高达 5000 Hz 的频率（相当于 300,000 rpm）以平面运动方式移动金刚石刀尖。 两个线性执行器被异相驱动，以创建一条刀具路径，通过改变激励电压的幅度、频率和相位，该刀具路径可以从线性变为椭圆形再变为圆形。 目标是通过将最小特征尺寸从 25 微米提高到 1 微米，将特征公差从 2 微米提高到小于 200 纳米，同时在各种材料中产生光学质量的表面光洁度，从而显着提高机械加工的能力。 微机电系统 (MEMS) 使设计人员能够在芯片上创建微型机械振荡器、光网络组件和生物实验室，但使用商业半导体制造设施创建此类设备所需的高成本和长交货时间一直是其广泛接受的障碍。 半导体技术是为使用标准 CMOS 处理的大批量电路而设计的，而许多 MEMS 器件需要小批量、具有更复杂的结构（例如移动三维微镜阵列）并且需要硅以外的材料。 过去的 MEMS 加工研究一直强调高速主轴，同时引入了一种新技术，避免了旋转主轴固有的跳动问题，从而可以创建更小、更精确的特征。 与普通金刚石车削相比，由此产生的切屑几何形状可减少加工力并减少刀具/工件接触时间，从而延长刀具寿命并扩大工件材料（塑料、金属和陶瓷）的范围。 这些实验旨在研究小切削深度下的材料流动，定义工艺极限并确定不同工件材料的最佳切削条件。 原型设备的制造将展示机械、光学和流体结构在 3D 中的集成。