ReLaXd: towards a large and yet accurate X-ray detector

Smaller, faster and even more accurate; that is the chip industry's goal. Yet for large and precise detection systems this gives rise to problems and conflicting requirements. The ReLaXd project has come up with the solution: pixel chips are placed closely next to each other in a lattice to obtain a large detection surface that still has a high spatial resolution and a rapid registration.

The Medipix pixel chip has already been successfully applied in various types of rapid imaging equipment. As one chip only has a surface area of 14 by 14 millimetres, several chips need to be combined to produce a single detector with a large active surface. Combinations of 2 by 2 and even 4 by 2 chips have already been produced.

ReLaXd (high-REsolution Large-Area X-ray Detection) now wants to produce a detector with far more Medipix chips. This can only be realised if the chips are placed extremely close to each other so that the detector contains as few 'blind spots' as possible where no signal can be measured. The chips must therefore be positioned with extreme accuracy and it must also be possible to cool them.

Furthermore, innovation is needed in the area of the electrical connections with the chip. The standard approach - attaching wires to the upper surface of the chip - is no longer satisfactory. The industry is extremely interested in the new Through Silicon Via connection, since it can be applied in 3-D electronics.

ReLaXd is a Eureka designated partnership between Nikhef, Panalytical, IMEC and Canberra Olen. The European Commission is funding the project together with SenterNovem and the Flemish Government (via IWT).

Partners in this project are:
Canberra, a company that produces semiconductor detectors. Nikhef obtains silicon and germanium detectors via Canberra's division in Olen, Belgium.
IMEC, the largest independent European research centre in the area of micro- and nano-electronics, nanotechnology, design methods and technologies for ICT systems.
Panalytical, a company that develops and produces equipment for the analysis of materials using X-rays.

Further information can be found on the Relaxd page or can be obtained from Jan Visser who works in the Detector Research & Development group.