The ES/9000 glass ceramic thermal conduction module, design for manufacturability

The highest performing models of IBM´s recently announced ES/9000 family of mainframe computers utilize a new high-performance thermal conduction module (TCM). To achieve improved system performance, a newly developed corderite glass ceramic material with an internal copper metallurgy and top surface thin film wiring was used. The new glass ceramic material provides a superior dielectric constant of 5.0, which yields a 27% improvement in propagation delay over IBM´s existing 3090 alumina technology. The internal copper metallurgy yields a lower electrical resistance than the molybdenum metallurgy which was used with the alumina ceramic, notwithstanding a 40% reduction in conductor area. To meet the system wireability and chip count criteria, the area of the substrate was increased about 26%, the internal via and wiring pitch was decreased by 10%, and the total number of layers was increased by 66%