Low dielectric constant new materials for multilayer ceramic substrate

A discussion is presented of the development of a low dielectric constant glass-ceramic material system with a thermal expansion coefficient and flexural strength that could be further improved. This system consists of quartz glass, cordierite, and borosilicate glass and features the following advantages. (1) This system can be sintered at below 1000°C, so it is possible to use low electrical resistivity conductors, such as Au, Ag, Ag-Pd, and Cu as signal lines and interconnection. (2) The low dielectric constant can be realized in the 3.9-4.7 range. (3) The thermal expansion coefficient (TEC) can be controlled to match that for the carried chips. (4) The flexural strength (2000 kg/cm²) is relatively high. The green sheet lamination technology was used to develop a low dielectric constant multilayer glass-ceramic substrate with Ag-Pd wiring. This substrate can be used as a high-speed VLSI multichip packaging substrate