Assembly line production in a vacuum

Physik Instrumente (PI): A special challenge for the Eschbach engineers was an assembly line production under vacuum conditions with 10-6 mbar. The fully automated sandwich assembly of a carrier with a precision foil and a counterholder on the rear side had to be integrated in the production process. The 1 m² foil has to be positioned in relation to the carrier with an accuracy of +/- 20 µm. Since the position of the carrier varies, the assembly process, which could not take longer than 10 seconds, could only be done with a positioning system with six degrees of freedom. For the desired travels of 50 mm in the direction of assembly and 20 mm perpendicular to this, a SpaceFab from Eschbach was recommended due to its low height.

The system developed for this application can easily move loads of 100 kg with low vibration, fast and very precisely. The key to this is an ingenious combination of a mechanical system, spindle pitch and high encoder resolution. Three-phase servo motors that were also specially designed for this application ensure the necessary dynamics. A vacuum-compatible holding brake was also redesigned since the solutions on the market did not meet the requirements of this application regarding material properties and power loss. PI miCos also assumed responsibility for the software for controlling the sandwich assembly and the integration of the sensor and camera measurements as well as for the monitoring of the gripper magnets. The medium-sized company thereby proved that it was absolutely able to handle the requirements for complex multidisciplinary high-tech projects.

The miCos GmbH was founded in Eschbach near Freiburg, Germany in 1990. As PI miCos, it now belongs to the company group of PI (Physik Instrumente), located in Karlsruhe, Germany. With currently more than 50 employees, PI miCos develops, produces and markets innovative systems and components for high-precision positioning applications throughout the world. A main focus is on optical measurement technology in research and industry. For this purpose, PI miCos offers customized system solutions with multiple axes in addition to a comprehensive standard program. Wide-ranging application know-how guarantees the implementation of technically demanding solutions. Flexible positioning systems for ultra-high vacuum applications with parallel-kinematics and six degrees of freedom are an example of this, as are systems with linear motors and air cushion bearings.