Development of an automatic characterisation system for silicon detectors

The CMS experiment will be equipped with the largest silicon tracker in the world. The tracker will consist of about 25,000 silicon sensors which will cover an area of more than 200 m sup 2. Four quality test centres will carry out various checks on a representative sample of sensors to assure a homogeneous quality throughout the 2((1)/(2)) years of production. One of these centres is based in Vienna. To cope with the large number of sensors a fast and fully automatic characterisation system has been realised. We developed the software in LabView and built a cost-efficient probe station in house by assembling individual components and commercial instruments. Both the global properties of a sensor and the characteristic quantities of the individual strips can be measured. The measured data are immediately analysed and sent to a central database. The mechanical and electrical set-up will be explained and results from CMS prototype sensors are presented.