Aqueous solution blending route for preparing low dielectric constant films of polyimide hybridized with polytetrafluoroethylene

摘要

High performance polymer materials with low dielectric constant, good thermal stability and excellent mechanical property are on demand in the next generation integrated circuit devices as the interlayer dielectrics. This study reports the preparation of polyimide hybridized with polytetrafluoroethylene (PI/PTFE hybrid) films with low dielectric constant, excellent thermal stability and mechanical strength by a facile approach. The PI/PTFE hybrid films were prepared by an aqueous solution blending method, that a synthesized water soluble poly(amic acid) ammonium salt was blended with a PTFE aqueous emulsion, followed with spin-coating and thermal imidization. The PI hybrid film (40 wt% PTFE) showed a lowest dielectric constant of 2.25 (at 1 kHz). Meanwhile, the PI/PTFE hybrid films exhibited good thermal stability of the 5% weight loss temperatures (T_(5%)) higher than 520 °C, and glass transition temperatures (Tg) higher than 285 °C; as well as excellent mechanical properties of the tensile stress, modulus, and elongation at break being 84-127 MPa, 0.94-1.86 GPa, and 56-118%, respectively.