AUGUST 21, 2008 â�� Aerotech today introduced the ALS130H series linear motor stage which it claims features sub-nanometer resolution, superior bi-directional repeatability, and low velocity performance.
Ideal for high-performance test, measurement, inspection, and other demanding applications, the ALS130H employs a center-driven, non-cogging linear motor as the driving element. Since the linear motor is a direct-drive device, there is no backlash, windup, or "stiction" normally associated with a lead screw or ball-screw drive, says the company. The moving magnet track design eliminates the need for cable management and further improves long-term reliability.
The linear motor drive also offers the advantage of higher speeds and accelerations. The compact yet powerful linear motor drives the ALS130H to a peak unloaded acceleration of 1 g and a maximum velocity of 300 mm/sec. The result, claims Aerotech, is a high-performance stage with outstanding throughput that significantly outperforms comparable high-accuracy screw-driven stages.
Outstanding step-to-step resolution is critical for alignment applications; company representatives say the ALS130H meets this demand with a resolution of 0.5 nm. The direct-drive linear motor allows the ALS130H to make precise, small resolution steps, which is particularly important in alignment applications where step accuracy is critical. The linear motor and high-resolution encoder system also provide excellent in-position stability.
According to the company, the ultra-stiff construction and compact two-piece design result in a stage with unmatched geometrical tolerances. Straightness and flatness for the standard ALS130H is <±2 µm over the entire travel.
Designed for vibration-free motion, the ALS130H utilizes precision anti-cage-creep cross-roller bearings for motion. Since neither the bearing system nor the drive system utilize any recirculating elements, the ALS130H exhibits the ripple-free motion required for high-precision scanning and inspection applications, say company representatives.