MCM SUBSTRATE WITH HIGH CAPACITANCE

It is well established that thin film capacitors have good electrical characteristics; for that reason they are often used in high frequency applications. We have investigated planarization of bottom capacitive electrodes which must make direct contact with a co-fired ceramic sur face, and adjustment and control of the Thermal Coefficient of Expansi on (TCE) difference between high dielectric constant material and the base MCM ceramic substrate. Combining thin film capacitors with MCM su bstrates can result in high frequency decoupling capacitors (with 100x the capacitance of comparable co-fired thin layer alumina constructio ns), space savings, and significant improvement in performance over co nventional discrete chip capacitors.