Large scale multilayer glass-ceramic substrate for supercomputer

A large-scale multilayer glass-ceramic (MGC) substrate having a low dielectric constant (7.8) and a high flexural strength has been developed by a highly accurate green-sheet technology. The substrate has an area of 225 mm×225 mm and is 5.5 mm thick. A low electrical resistivity (3 μΩ-cm) can be realized by using a gold paste system is forming the conductors. The substrate can support high-density pattern processing due to the highly accurate process. Shrinkage can be controlled to 13.0%±0.3%, in spite of the large dimensions, by using shrinkage-control technology. The MGC substrate was used in the multilayer substrate (MLS) for supercomputer multichip packages. For the MLS, polyimide layers with signal line were formed on the MGC substrate. The new substrate has 78 layers, of which 13 are conductive layers, and 11540 I/O pins. The substrate houses up to 100 VLSI chips in a 225-mm square area, large scale MGC substrate properties, and supercomputer applications