The intermediate silicon layers space frame

The Intermediate Silicon Layers (ISL) detector is being built as part of th e Collider Detector at Fermilab (CDF) upgrades for the run ii operation of Tevatron. The ISL Space Frame (SF) is a structure that defines the location of the ISL detectors, supports the micro-vertex silicon trackers (SVXII, L 00) as well as the beryllium beam pipe. The SF design, project and construc tion are challenging due to the precision and mechanical stability requirem ents that must be achieved using a minimum amount of material. The SF is a high-precision light structure made of carbon fiber designed and built at t he INFN Pisa and shipped at Fermilab in summer 1999. In this contribution w e describe in detail the SF construction phase and the accuracy obtained.