Microglide™ Air Bearing Positioning Systems
Microglide™ N 250
- Open frame design for dual-sided workpiece access and fixturing
- Nested single plane XY air bearing configuration provides superior geometric accuracy
- Magnetic preload with integral damping provides smooth scanning and fast settling
- Optional granite bridge assembly for mounting overhead equipment
- Linear incremental encoder or laser interferometer feedback
- Cleanroom compatible
- Ideally suited for:
- Optical Disk Manufacturing
- Microelectronic Test and Inspection Equipment
- X-Ray Lithography
Small Open Frame Positioning Platform
The Microglide N250 features a nested coplanar frame-in-frame dual axis design. This configuration allows access to the workpiece from both above and below, to facilitate the use of optics, bottom illumination, vacuum chucks or other application specific subsystems. The X and Y frames are made from precisely machined rigid meehanite iron castings. This produces exceptionally stiff slides with excellent vibration damping characteristics. The lift air bearings all reference the same optically flat lapped granite base. This minimizes flatness, pitch, and roll errors typically found in conventional stacked-stage systems, plus the frame-in-frame design reduces overall system height.Two side-mounted zero-cogging brushless linear servomotors drive each axis of the Microglide N250. The motors operate in parallel to create a resultant central drive force while maintaining an open frame design. This technique eliminates the twisting torque inherent in single sided drives. Anorad's linear motors are completely non-contacting to eliminate the backlash, friction, and wear issues normally exhibited by conventional mechanical drives.
The laser feedback option features a frequency stabilized, double pass laser interferometer with orthogonal plane mirrors. The mirrors are mounted on the inner axis slide with the laser beams aligned to intersect at the height of the customer part, thus minimizing Abbé offset errors. Linear optical encoder feedback is available using a diffraction grating tape scale.
Options include: additional rotary, vertical, tip, and tilt axes; zero-jitter air brake; fixed overhead granite bridge; support frames; vibration isolation systems; servo controllers and custom travels.
Specifications
| Performance Specification | Units | Model N250E | Model N250L |
|---|---|---|---|
| Travel 1 | mm | 250 x 250 | 230 x 230 |
| Feedback System | - | Optical Linear Encoder |
Plane-Mirror Interferometer |
| Resolution 2 | nm | 0.5 - 500 | 0.31 - 10 |
| Repeatability | µm | ± 0.3 | ± 0.15 |
| Positioning Accuracy 3 | µm | ± 0.5 | ± 0.25 |
| Flatness of Travel |
µm | ± 1.0 | ± 1.0 |
| Straightness of Travel |
µm | ± 1.0 | ± 0.25 |
| Orthogonality |
arc sec | ± 1.0 | ± 0.5 |
| Pitch, Roll and Yaw | arc sec | ± 1.0 | ± 1.0 |
| Mazimum Load Capacity 4 | kg | 35 | 35 |
| Maximum Velocity 5 | mm/s | 500 | 500 |
| Maximum Acceleration 4 | m/s 2 | 10 | 10 |
| Scanning Velocity Range 5 | mm/s | 350 | 350 |
| Average Velocity Ripple 6 | % | < 1.0 | < 1.0 |
| Position Stability 6 | counts | ± 1 | ± 1 |
| 25 mm Step-&-Settle Time 6 | ms | < 300 | < 300 |
Notes: Specifications are based on overall travel of each axis (significantly better positioning accuracy is possible over shorter travels) and operation in a controlled environment with Anorad approved vibration isolation system. Additional performance, travel, and configuration options are available. Contact Anorad for details.
- Additional 3 mm overtravel at each end before hard-stops.
- Resolutions available to 0.5 nm (encoder with 8192 x multiplier) or 0.31 nm (laser with l/2048 interpolation).
- After error mapping axes.
- Load based on lift bearing capacity. Applied load may determine maximum acceleration.
- Dependent upon system resolution and data rate.
- Typical dynamics for configured load, acceleration, velocity, resolution and data rate.
Carriage mounting holes are made to meet specific end user requirements.
325 x 325 mm opening in center frame