Colloidal processing of polymer ceramic nanocomposites for integral capacitors

Abstract

Polymer ceramic composites form a suitable material system .for low temperature fabrication of embedded capacitors appropriate for the MCM-L technology. Improved electrical properties such as permittivity can be achieved by efFcient filling of polymers with high dielechic constant ceramic powders such as Lead Magnesium Niobate-Lead Titanate (PMVPT) and Barium Titanate (BT). Photodefinable epoxies as the matrix polymer allow fine feature definition of the capacitor elements by conventional lithography techniques. The optimum weight percent of dispersant is tuned by monitoring the viscosity of the suspension. The dispersion mechanism (steric and electrostatic conhibution) in a slightly polar solvent such as PGMEA is investigated @om electrophoretic measurements. A high positive zeta potential is observed in the suspension, which suggests a strong conhibution of electrostatic stabilization. By optimizing the particle packing using a bimodal distribution and mod$ed processing methodology, dielectric constant greater than 135 was achieved (PMN-PT + epoxy). Suspensions are made with the lowest PGMEA content to ensure the e c i e n q of the dispersion and efficient particle packing in the driedfilm. Improved colloidal processing of nanoparticle-filled e p o v is a promising method to obtain ultra-thin capacitor films (< 2 microns) with high capacitance density and improved yield. Capacitance of 35 nFicm2 was achieved with the thinnestfdms (2.5-3.0 microns).

Solubility and aging of lead magnesium niobate in water

“…The previous studies on this subject include the preparation of lead magnesium niobate-lead titanate (PMN-PT) suspensions in solvents other than water [5][6][7]. PMN-PT powders can be dispersed in organic solvents, to get well-dispersed suspensions.…”

Poly(vinylidene fluoride)/ CaCu3Ti4O12 and La doped CaCu3Ti4O12 composites with improved dielectric and mechanical properties

“…Temperature-dependence of dielectric relaxation is explained by Havriliak-Negami (H-N) function [32][33]:…”

Influence of Dispersing Agents on the Solubility of Perovskites in Water

“…[6] The manufacturing of multilayer electronic ceramic devices composed of perovskite materials such as PMN generally involves a colloidal process which requires preparation of stable suspensions. [7] Perovskite materials having the general chemical formula, ABO 3 such as PMN are composed of a cation at the A site that is generally soluble in water and a cation at the B site that is only slightly soluble over the most of the pH ranges. [8,9] Therefore, the leaching of lead magnesium niobate in water is a major issue in colloidal processing.…”