LOW DIELECTRIC-CONSTANT NEW MATERIALS FOR MULTILAYER CERAMIC SUBSTRATE

VLSI package development continually demands new packaging technology to accommodate high signal transmission speed, high wiring density, and high frequency pulse requirements for a substrate. High signal transmission speed especially requires development for a low dielectric constant material. This was the impetus for the development of a low dielectric constant new glass-ceramic material system with thermal expansion coefficient and fluxural strength that could be further improved. This material system consists of quartz glass, cordierite and borosilicate glass, and features the following advantages. 1) This material 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 interconnections. 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. By using the green sheet lamination technology, the low dielectric constant multilayer glass-ceramic substrate with Ag-Pd wiring was developed, which can be applied to the high-speed VLSI multichip packaging substrate. © 1990 IEEE