Electrical properties of co-fired high and low dielectric constant multilayer package materials

The problems encountered in mixing high-dielectric-constant (high-K) lead-oxide-based capacitor layers in the same body as low-dielectric-permittivity (low-K) signal distribution layers were studied. Compatibility between the high-K capacitor material and low-fire (850-950 degrees C) glass-Al/sub 2/O/sub 3/ substrates was investigated. Most high-K ceramic materials sinter at temperatures above 1000 degrees C; firing at 900 degrees C or lower can result in a porous structure with poor electrical properties.<>