Use of dispersant in high K polymer-ceramic nano-composite to improve manufacturability and performance of integral capacitors

Integral or embedded capacitor technology could increase packaging density, improve electrical performance and reduce assembly cost compared with traditional discrete capacitor technology. Developing a successful dielectric material that satisfies electrical, reliability and processing requirements is one of the major challenges for incorporating capacitors into the large-area substrates. Polymer-ceramic nano-composites have been of great interest as the high dielectric constant (K) material because they combine the processability of polymers with the desired electrical properties of ceramics. Nevertheless, there are some technical barriers for the polymer-ceramic composites to be used in the organic substrates. Most significantly, for a very high dielectric constant of about 150 as reported so far by our group, a necessary rather high ceramic filler loading (85% by volume) gave problems in well dispersion of the ceramic fillers within the organic matrix, and there was almost no adhesion towards other layers in the printed circuit board structure. In order to develop polymer-ceramic nano-composites with a dielectric constant as high as possible together with compatibility toward manufacturing process of organic printed circuit boards, we have introduced dispersants into the formulations. Comprehensive formulation techniques have resulted in a much higher dielectric constant (e.g., typically over 65 at a ceramic loading of 40% by volume) as well as excellent adhesion performance.