Very low mass microcables for the ALICE silicon strip detector

The ALICE Inner Tracker silicon strip detector layers will use kapton/aluminium microcables (12/14 Pm thickness) exclusively for all interconnections to and from the frontend chips and hybrids, completely eliminating traditional wirebonding. Benefits are increased robustness and an extra degree of dimensional freedom. Utilising a lowpower, low temperature and low-force (10-15 grams) single-point TAB bonding process, aluminium traces are directly bonded through bonding windows in the kapton foil to bond pads on the chip, detector and hybrid. The same technique is also used to interconnect these microcables to create multi-layer bus structures with “bonded via’s”. Working in close collaboration, the SRTIIM Kharkov and NIKHEF UTRECHT groups are involved in the design, production and testing of these cables, as well as research of positioning and assembly methods. A double-sided detector using prototype cables has been installed in the NA57 experiment in 1998.