Posted to News on 5th Sep 2007, 21:11
Air bearing stage features active preload
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 superior performance in pitch, yaw, roll, straightness and flatness, 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 290mm and an overall height of 85mm, the new range supports centralised loads of up to 35kg with a working travel range from 50-500mm in six models.
A choice of three linear encoder technologies enables positioning resolutions of between 1.0 microns and 0.001 microns. Positioning accuracy across the range is to with +/-1 microns for a standard 50mm travel stage and up to +/-0.2 microns for the HALAR (high-accuracy system –linear error correction for accuracy and repeatability) calibrated version. Maximum speeds up to 2m/s and acceleration to 2g are dependant upon load and system resolution requirements.
No hysteresis
The powerful BLMC brushless and cog-free linear motor used on the ABL1500 provides exceptionally smooth backlash-free motion with no hysteresis and excellent in-position stability. A choice of PWM or linear stage amplifiers provides users with a performance profile that matchess the application. The high-power capabilities of Aerotech's HP series PWM amplifiers suit micron-level resolution requirements and Aerotech's HL series linear amplifiers provide the improved stability and 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 and 1.0 microns. For ultimate high resolution the LN amplified sine wave series provide 0.001 to 0.2 microns resolution and is usually accompanied with the HALAR calibration option, which uses a pre-calculated, laser interferometer-generated, look-up table in the Aerotech control software that is dynamically maintains 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, thereby keeping downtime to an absolute minimum.
Maximum 32 axes
Motion control options for the ABL1500 range include the software-based A3200 Digital Automation Platform for up to 32 axes of Firewire-interfaced high-performance motion with optional integrated machine controls for HMI, PLC and vision control modules. The A3200 uses the Microsoft .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++, VisualBasic, Delphi and Labview.
The A3200's distributed control architecture delivers fully deterministic position, velocity and time-based motion updates to Aerotech's Ndrive HP series PWM servo drives or HL series linear amplifiers, which are available in power ratings to 150A. The Ndrive also features an Ethernet 10/100 Base T interface that 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 system including special fixtures, machine base or other components and assemblies required by customers. 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-sales technical support.
