25 September 2007

Aerotech's new ABL1500 air bearing linear positioning stage

Aerotech's new ABL1500 air bearing linear positioning stage features active air preload, direct drive zero-cogging servomotors and sub-micron linear encoders for high throughput scanning and inspection applications in semiconductor, data storage, MEMS and other industries dealing with high resolution microstructures.

The active air preload is applied and averaged across the entire, meticulously prepared and extremely flat, bearing surface resulting in exceptional vertical and horizontal stiffness for a superior pitch, yaw, roll, straightness and flatness performance, even under heavy load conditions. As the stage design has virtually zero friction, a practically unlimited working life is possible with inherently minimal maintenance resulting in a very low overall cost of ownership. With a nominal stage width, including the integral cable management system, of 290 mm and an overall height of 85 mm, the new range supports centralised loads to 35 kg with a working travel range from 50 mm to 500 mm in six models.

A choice of three linear encoder technologies allows positioning resolution between 1.0 microns and 0.001 microns. Positioning accuracy across the range is to with +/-1 microns for a standard 50 mm travel stage and up to +/- 0.2 microns for the HALAR calibrated version. Maximum speeds up to 2 m/s and acceleration to 2 g are dependant upon load and system resolution requirements.

The powerful BLMC brushless and cog-free linear motor used on the ABL1500 is tried and tested to provide exceptionally smooth backlash-free motion with no hysterisis and excellent in-position stability. A choice of PWM or Linear Stage amplifiers provides the user with a performance profile that will match his application. The high power capabilities of Aerotech's HP series, PWM amplifiers will suit micron level resolution requirements and Aerotech's HL series linear amplifiers offer the much improved stability and greatly reduced noise levels that are essential for nanometre level resolutions.

Linear encoder options for the ABL1500 include the LT series with a choice of amplified sine-wave or 0.1 micron line-driver output for system resolutions between 0.005 microns and 1.0 microns. For ultimate high resolution the LN amplified sine wave series will provide between 0.001 microns to 0.2 microns resolution and is usually accompanied with the HALAR calibration option (High-accuracy system - linear error correction for accuracy and repeatability) which uses a pre-calculated, laser interferometer generated, look-up table in the Aerotech control software that is used to dynamically maintain ultra-high accuracy during the move profile.

The ABL1500 high performance air bearing stage is supplied in single or X-Y assembled configurations with optional orthogonality guaranteed to 2 arc-sec. Cable chain management systems for both single and dual axis versions are fitted as standard with provision for customers own electrical, air or other cabling included. Although designed for years of trouble-free operation, the cable chain management is the only ABL1500 component that has the potential for wear and its modular design (including connectors fitted to both cable ends) facilitates easily accessible replacement of individual cables or the complete chain assembly, keeping downtime to an absolute minimum.

Motion control options for the ABL1500 range include the software based A3200 Digital Automation Platform for up to 32 axes of FirewireR interfaced high performance motion with optional integrated machine controls for HMI, PLC and vision control modules. The A3200 uses the MicrosoftR .NET development environment to help reduce project development timescales and simplify device integration. Programming languages available include Aerotech's own AEROBasic or RS274 G-code, C, C++, VisualBasicR, Delphi and LabviewTM.

The A3200's distributed control architecture delivers fully deterministic position, velocity and time based motion updates to Aerotech's NdriveR HP series PWM servo drives or HL series linear amplifiers which are available in power ratings to 150 A. The Ndrive also features an Ethernet 10/100 Base T interface which may be used to add third party I/O and PLCs.

As a distributed control alternative for applications based on Ethernet networking, the ABL1500 air bearing stage may be driven and controlled with Aerotech's new Ensemble CP/MP/CL intelligent panel mount drives. Featuring Aerotech's AeroNet deterministic high-speed serial networking for up to ten axes, the new intelligent drive seamlessly combines a choice of PWM or linear amplifier technology and powerful motion controller to provide tightly synchronised precision motion with a generous complement of on-board I/O.

Aerotech can supply the ABL1500 stage as part of an engineered motion solution including special fixtures, machine base or other components and assemblies required by the customer. Aerotech systems are completely tested and delivered fully cabled with performance and calibration related documents included, along with motor parameter set-up data based on actual loading conditions. The scope of supply includes full product training and comprehensive pre and post sale technical support.

Contact: Cliff Jolliffe

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