Manufacturing of a Compact Micro Air Bearing Device for Power Micro Electro Mechanical System (MEMS) Applications Using Silica Film Assisted Processing

Abstract

The focus of this study is on the manufacturing of micro air bearings (MABs) using silica film assisted processing. Structure of the three-layer micro air bearing is described in detail and the salient process flow of etching and bonding is illustrated. The main manufacturing challenges and the methods adopted to overcome them are also presented. The uniformity of wet etching for nozzles with 20 μm in diameter to silica film is improved by adopting an ultrasound assisted method. Particular attention is given to the novel fabrication procedures for the second layer of MAB (with three depths on aft side). This paper develops new applications of silica film in Micro Electro Mechanical System (MEMS) processing for MABs to realize the etching of multi-depth on the same side and efficient three-layer bonding with increased bonding areas. A silica etch mask is proven to achieve a higher accuracy in surface topography when compared to a photoresist mask for multi-depth etching, resulting in precise depth and vertical control. The bonding rate of three-layer direct bonding for MAB is increased by 50% from 0.05 to 0.1 with the novel silica film protection method.

Prediction on Flow and Thermal Characteristics of Ultrathin Lubricant Film of Hydrodynamic Journal Bearing

“…Zhang et al [ 22 ] explored the mechanism of synergetic lubrication by both experiment and CFD, and emphasized the significant influence of lubricant viscosity. Other scholars also pay attention to the investigation of journal bearings [ 23 , 24 , 25 , 26 ]. Li et al [ 23 ] investigated the microbearings and found that the rise of temperature would weaken the load capacity and negatively influence the operating stability of microbearings.…”

“…Besides, Chen et al [ 25 ] focused on the fabrication of a biomimetic superhydrophobic surface in the application of a water-lubricated bearing, which enlarged the research scope of surface lubrication of bearings. Yu et al [ 26 ] developed new applications of silica film in micro air bearings, which broadened the manufacture craft of bearings. However, the interactions between the viscosity and temperature of lubricant should be further taken into consideration.…”

Multi-Physics Fields Based Nonlinear Dynamic Behavior Analysis of Air Bearing Motorized Spindle

“…The air bearing motorized spindle is commonly equipped in the ultra-precision machine, in which the rotor shaft is directly driven by usually a permanent magnet synchronous motor (PMSM) and supported by the air journal bearing [1][2][3][4]. Due to its compact structure, high efficiency, pollution free, high precision and other advantages, extensive studies of the ABMS have been conducted in the past few decades, which mainly focus on the dynamic characteristic of air journal bearing [5][6][7][8].…”

Design and optimization of a liquid ring thrust bearing

“…Furthermore, at the micro scale, friction and wear are much more sensitive to surface roughness, which is very difficult to control, and this renders the use of micro rolling element bearings unfeasible. These challenges prompted the development of novel lubricating systems for micro scale -examples of these are bearings levitated by air flow [13][14][15][16][17], electromagnetic or electrostatic force [18][19][20][21]. These techniques are highly effective of reducing friction, however need auxiliary energy input and complex control systems.…”