Dielectric Properties Of Calcium Copper Titanium Oxide Nanoparticles/Polyimide Hybrid Composites

With the rapid development of the electronics industry, the miniaturization ofintegrated circuit (IC) is significant development trends. The capacitors with highdielectric permittivity are the premise of IC. Inorganic/polymer composites havesignificant development potential because they can combine advantages from bothphases; that is, the high dielectric permittivity of ceramic materials and the goodmechanical strength and ease of processing of the polymer. In this paper, nanosizedcalcium copper titanium oxide particles (a-CCTO) were prepared by sol-gel method,and a-CCTO is amorphous ceramic. Then crystal copper calcium titanate particles(CCTO) were also prepared. Finally, a-CCTO/PI and CCTO/PI hybrid films wereprepared and the dielectric mechanism was also discussed.In this paper, nanosized a-CCTO prepared by sol-gel method at300°C wasamorphous. The dielectric permittivity of it decreases sharply with increasing thefrequency, and is much lower than the permittivity of CCTO sintered at1050°C inthe whole range. The a-CCTO/PI hybrid films were prepared by in-situ method at thelower doping concentrations, the nanosized particles disperse well and the films keepwell processing properties like pure PI. When the a-CCTO/PI hybrid films is3vol%,the dielectric permittivity is4.4, higher than that of CCTO/PI hybrid films (3.8)when the CCTO concentration is10vol%, and compared with pure PI, theincrement is obvious.The dielectric permittivity of a-CCTO/PI hybrid films is higher than that ofCCTO/PI hybrid films, which shows the dielectric property of a-CCTO/PI hybridfilms is not from a-CCTO particles. The interface activation energy Eawascalculated and show that the interface of a-CCTO/PI hybrid films many activeelectrons or charges, while the interface of CCTO/PI hybrid films is insulated. Thedefects of a-CCTO surfaces can supply effective electrons and the nanoparticles property enhances the defect density, so interfacial polarization is much strong.Therefore, the dielectric permittivity can be enhanced markedly in the lowerconcentrations.