Integral capacitor dielectrics based on polymer composites with specialty conductive fillers

Abstract

Integral passives have been considered an enabling technology for advanced next generation electronic system integration. Compared with their traditional discrete counterparts, they could increase packaging density, improve electrical performance and reduce assembly cost. Developing a successful dielectric material that satisfies electrical, reliability and processing requirements is one of the major challenges for incorporating capacitors into large-area substrates. Polymer based composites have been of great interest as high dielectric constant materials because they are compatible with organic substrate manufacturing processes. Ceramic and conductive particles have been introduced into polymer matrix to formulate composite dielectrics. Ceramic composites could give fairly balanced dielectric properties, but are difficult to achieve high dielectric constants because of poor processability at a high loading level of the ceramic fillers. Conductive filler composites have been found to exhibit high K with a loading level before the percolation threshold; however, they tend to be associated with a rather high loss, which would impose negative impacts upon their potential applications. Thus, specialty Conductive particles have been investigated to understand their effects on dielectric performance of the polymer conductive filler composites. The resulls showed that aluminum with selfpassivation and conductive particles with insulation coating over their surface could significantly suppress the loss of the composite dielectrics while demonstrating dielectric constant performance similar to those of polymer ceramic composites.