Abstract: Sealing and stress relief are provided to a low-fracture strength glass-ceramic substrate. Hermeticity is addressed through the use of capture pads in alignment with vias and through polymer overlays with interconnection between the underlying via or pad metallurgy and the device, chip, wire or pin bonded to the surface of the layer. Multilevel structures are taught along with a self-aligned sealing and wiring process.

Abstract: A method of fabricating a multilayer ceramic substrate with an internal conductive metallurgy circuit network, wherein additional green sheet material is added to the stack of ceramic green sheets during assembly to areas of the substrate outside of the conductive metallurgy to compensate for the volume of conductive metal paste to thereby eliminate or minimize substrate distortion during the sintering operation. An unsintered intermediate green ceramic substrate made up of green ceramic sheets with via holes and conductive metal lines on the surface which collectively form the circuit network where the improvement is additional green ceramic material in the substrate in areas outside of the conductive metallurgy network to compensate for the additional volume of material of the conductive metal which additional material provides a more uniform ceramic material density through the substrate.