Air Bearings Provide Submicron Positioning

Air Bearings Provide Submicron Positioning Anorad's new Microglide air bearing systems provide smooth, virtually frictionless motion, allowing extraordinary control to be readily achieved in precision positioning and scanning processes. This makes them an ideal choice for use in lithography, semiconductor manufacture, inspection, metrology and similarly demanding applications. Microglide air bearings are offered in a wide range of versions, including T-shaped configurations which combine economy with submicron positioning repeatability, and nested N-type configurations which use a frame-in-frame design to allow full access to both sides of the workpiece. Anorad also offers versions which are custom engineered to suit specific user requirements. In all versions, a thin film of pressurised air supports the applied load. High accuracy is achieved by ensuring the air gap of just a few microns remains constant, using a variety of highly stable preloading techniques. As they effectively distribute the load over a wide area, the air bearings have a built-in averaging effect which compensates for minor irregularities in the reference surface, ensuring smooth precise operation. Powered by brushless zero-cogging motors, Anorad Microglide air bearing systems are available with a choice of high-resolution feedback devices, including optical incremental encoders, laser interferometers and signal interpolators.