Polyimides containing cycloaliphatic segments for low dielectric material

Abstract

New polyimides have been synthesized by the reaction of 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA) or/and 5-[2,5-(dioxotetrahydrofuryl)]-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (DOCDA) with 4,4′-methylene dianiline (DDM). Polycondensation reactions were carried out in N, N-dimethylformamide solution and the resulting polyimides gave flexible free-standing films. The introduction of alicyclic moieties in the polyimide backbone improved the solubility of the resulting polymers and facilitated their processing while maintaining a high thermal stability. The dielectric constant values (measured at 10⁶ Hz at room temperature), were found in the range of 3.14–2.83 and decreased with increasing of the alicyclic units content.