High-end automation, manufacturing, metrology, and test applications rely on precision motion control systems. In 24/7 operations, maintenance-free positioning systems gather additional bonus points and when a motion principle also is devoid of particle generation, people who design products in cleanrooms, such as optical and semiconductor process and test engineers, are happy, too.
A good place to start is the combination is an air bearing slide with a frictionless, non-contact, direct-drive linear motor and fine pitch non-contact linear optical encoder – the right ingredients for an unlimited service life.
Air bearing slides provide the highest level of performance in terms of precision, straightness, flatness, and position repeatability. In an air bearing slide, the table is floating on a thin film of air, only a few micrometers thick. The high precision is made possible by a combination of the very precise grinding and coating processes of the planar guideways the moving table floats upon and the so-called surface averaging effect. This principle allows for higher precision than the best mechanical linear guides, such as high-end crossed roller bearings or circulating ball bearings. And unlike these mechanical bearings, air bearing slides don’t need lubricants, because their surfaces don’t make mechanical contact, which is also why they don’t generate particles.
The frictionless design of an air bearing slide benefits closed-loop operation with a high performance motion controller resulting in rapid response, settling, and excellent dynamic behavior.
Air bearing positioning stages come in a wide range of sizes and payloads – mostly for higher load applications but ultra-small designs are also possible.
In addition to its extensive line of large air bearing tables and gantries, PI has a long history of designing very compact air bearings for industry and research. PI engineers have been working on an ultra-compact motorized air bearing linear slide driven by a compact voice coil actuator. The A-142 provides 10mm (0.4”) of linear travel while supporting loads up to 3kg (6.6lbs). Its high-performance voice coil motor can accelerate with 2g’s and achieve a top speed of 450 mm/sec. An integrated optical linear encoder provides 5nm resolution, the mechanical performance is 0.05µm minimum incremental motion, and higher resolution encoders for even better accuracy are also available. The combination of performance and size makes this compact linear motion system the ideal component for nanopositioning applications in clean room environments. The A-142 boasts a low profile of only 27mm (1.1”) and its moving platform size measures only 75x80mm (≈3x3 ¼”) .
The new A-142 miniature slide complements the A-141 miniature linear stage.
For vertical mounting, a pneumatic counterbalance (force compensation) is available. High performance motion controllers and air filter kits are also offered.
The A-142 miniature air bearing linear stage is ideally suited for high-precision motion applications, such as surface metrology, fast photonics alignment, optics positioning, and scanning. Its noncontact design enables its use in cleanroom test and production environments.