Design and testing results of a long Flexible Printed Circuit for the ATLAS High Granularity Timing Detector

The High Granularity Timing Detector for the ATLAS upgrade is under construction to meet the challenges of the HL-LHC. The silicon detectors along with the electronics are installed in two double-sided disks per end-cap and consist of basic units (called modules) connected to the peripheral electronics by Flexible Printed Circuit cables. The reduced space between disks and the positioning constraints as well as the large number of modules pose additional challenges for the power supply distribution and the readout system. We present the design and test results for a 2-layer Fexible PCB with a maximum distance of 75 cm between the connections.