Integral thin film capacitors: Materials, performance and modeling

Integral thin film capacitors offer great potential for high density, high speed, high I/O and low voltage IC packaging. They can be used to replace discrete surface mount capacitors for bypassing, decoupling, termination and frequency determining functions. Ceramic-polymer nanocomposites constitute one of the finest options as dielectrics in the fabrication of integral thin film capacitor arrays. The dielectric behavior is influenced by particle size of the ceramic, distance between particles and ceramic/polymer interface and interphase, if any. One major challenge in understanding the electrical behavior of polymer ceramic composites is the lack of viable models describing the characteristics of the composites. In the absence of such models the ultimate materials limit/performance and direction to proceed with their synthetic design are unknown. This problem has become even more acute recently as there is a deliberate effort to use smaller and smaller ceramic particles (nanoparticles) to improve processability and produce thinner dielectric films or printing inks for direct write / screen-printing applications. With decreasing particle size the influence of the interphase region becomes more dominant. In this paper we present our work on the interfacial influence of the ultimate performance of materials/application limits in terms of dielectric constant, loss and thermal stability as a function of particle size and loading of ceramic, polymer matrix and interphase characteristics. Complex Nonlinear Least Squares (CNLS) methods employed in the network modeling of ceramic- grain boundaries has been extended to test the case of Polymer-ceramic nanocomposites.