Thinned epitaxial silicon hybrid pixel sensors for the PANDA experiment

First prototypes of hybrid pixel assemblies using thinned epitaxial silicon pixels as the sensor element have been produced and tested as part of the ongoing programme to develop a custom pixel-based solution for the innermost layers of the tracking system of the PANDA experiment. Results were obtained from assemblies with three different epitaxial thicknesses of 50, 75 and 100 μm. The front-end chip for PANDA is still in development at this time and therefore the ALICE pixel front-end chips and readout chain were used. Basic detector characteristics, bump-bonding yield and tests with various radioactive sources are presented.