Optical inspection, laser cutting or marking, but also industrial measuring technology and microscopy require positioning systems which offer high travel accuracy and stability and that are as fast as possible in order to achieve high throughput. To be able to offer solutions to the most diverse applications, PI (Physik Instrumente) has two product lines of XY stages with different kinds of motors in its portfolio.
These compact positioning systems work in the X and Y direction with travel ranges of 100 to 300 mm, they achieve speeds to 500 mm/s, and position with a high repeatability (unidirectional to 0.05 µm). Integrated, high-resolution linear encoders measure the position directly at the platform; nonlinearity, mechanical play, or elastic deformations have, therefore, no influence on position measuring. Furthermore, the planar design with a flat profile minimizes stacking errors and increases the stiffness. Variants with 100 mm also have a large aperture in the centre which makes samples or workpieces accessible from above or below.
The XY stages are controlled by PI controllers or by an EtherCAT® based ACS control module, which additionally offers event-based triggering for the control of a laser or measuring tool in correlation to a motion pattern.
Motor Choice for Different Requirements
Either linear motor direct drive (V-731, V-738, and V-741) or stepper and DC motors (L-731, L-738, and L-741) are the driving force behind the XY stages. The three-phase magnetic linear motors dispense with mechanical components in the drivetrain and transfer the drive force directly to the motion platform without any friction. This means that velocities of up to 500 mm/s are possible. The ironless motors are particularly suitable for positioning tasks with the highest demands on precision because there is no undesirable interaction with the permanent magnets. This allows smooth running even at the lowest velocities and no vibration occurs at high velocities.
The L-731, L-738, and L-741 XY stages work with velocities to 90 mm/s. It is possible to use either stepper or DC motor to drive the precision ball screws. The two-phase stepper motors also generate a high torque at lower velocities; the DC motor variants are recommended for applications that require high running smoothness and higher velocities.