AUSTRALIAN Baldor has released a unique new type of X-Y positioning stage, which provides rapid sub-micron positioning over very large working areas.
Based on a combination of stepper and piezo-electric linear motors for coarse and fine positioning, the stage is available with travels of up to 3 x 1.5m, for payloads of up to 1.8kg.
These features provide scope for OEMs to improve productivity on a wide range of test, inspection and handling equipment involving ultra-fine positioning, such as wafer probing, fibre optic assembly, and biomedical sample manipulation.
Called NanoStepper, the stage provides two axes of movement implemented using a novel combination of linear stepper and linear piezo-electric friction motors.
The linear stepper motor with its frictionless air bearing provides very fast movement for coarse positioning of the payload, with a velocity of 1.5 metres/second and acceleration of 19.6 metres/second/second.
Mounted on this stepper motor is a piezo-electric friction motor which performs the subsequent fine positioning. This motor moves payloads at 100mm/s over a 10 x 10mm area, and offers an optical encoder feedback resolution of 10nm and a repeatable accuracy of <30nm.
This combination of speed and precision is believed to be unmatched on the commercial market today.
By employing this combination of stepper and piezo motor technology, Baldor believes that OEMs can both boost the productivity of automation, and open up new markets for equipment in areas served to date by application-specific engineering programs.
In addition to productivity enhancements, the NanoStepper stage provides its X-Y positioning capability within an exceptionally small profile of just 31mm.
This is around half the height (or less) of a combination of a conventional air bearing stage and a piezo motor for example - a technology currently used by some OEMs producing ultra-fine positioning - and smaller still than any system based on rotary components such as belts or ballscrews and servo motors.