RF Capacitor Material for Use in Printed Circuit Board
A novel ceramic-functional-particle-filled polymer composite material has been developed for the use either in discrete elements on the printed circuit board or in being embedded within the packaging substrate for high frequency circuit applications. This material provides the desired properties such as low loss at high frequencies, about 0.002 or less up to 10GHz, and high dielectric strength, among other improved properties. The electrical properties were influenced significantly by the ceramic-functional-particle, i.e. type and particle size/distribution in the polymer matrix. Their contributions to the electric strength and temperature stability of capacitance which is an important material issue for practical device application will be discussed. In addition, capacitance tolerance for manufacturing embedded RF capacitor will be presented in terms of etching uniformity to minimize the variation of the capacitor electrode areas.