The electronics hybrid of the ATLAS-SCT endcap detector modules

An electronics hybrid has been developed for the ATLAS silicon microstrip tracker endcaps. The high-density interconnect board carries 12 readout ASICs, as well as ASICs for the optical data transmission. Special requirements are that this hybrid has to be double sided, radiation hard, and low mass. A six-layer flexible circuit in copper-polyimide technology has been chosen for this purpose. It is folded around a highly heat conducting carbon-carbon composite substrate to form the rigid double-sided hybrid. Adequate thermal, mechanical, and electrical performance of the hybrid has been demonstrated. The production of the hybrids started in May 2003.