Microfabricated Fluid Dynamic Bearing

Abstract

A fluid dynamic bearing formed by a microelectromechanical systems (MEMS) wafer-level batch-fabrication process is provided. The process results in a high performance and high reliability fluid dynamic bearing having features including higher bearing lifetime at high RPM, improved bearing stiffness, durability and thrust/restoring forces capabilities. The present invention is especially useful with small form factor disc drive memory devices having constraints in motor height, such as a 2.5 inch disc drive, requiring high performance including high rotational speed and large areal density. A sacrificial layer is utilized in the process to simultaneously form symmetrical facing surfaces of relatively rotatable components. The facing surfaces define, therebetween, a desired feature, such as a journal bearing, a thrust bearing, a fluid channel, a fluid reservoir, a capillary seal, pressure generating grooves, and other profile geometries. Such geometry control allows for design freedom in obtaining a desired bearing performance and stiffness.

Dependencies are inferred from the claim text.