Low dielectric constant fluorinated polymers and methods of fabrication thereof

摘要

Low dielectric constant polyimides formed from an optionally fluorinated dianhydride and a fluorinated diamine are described. The fluorine containing constituents are sterically disposed so that the dipole moment of the constituents tend to cancel out. Since fluorine containing diamines are generally nonreactive, to achieve a polyimide of high enough molecular weight to be practically useful, a method of fabrication of a high molecular weight polymer from monomers of low reactivity is provided. The monomers, such as a diamine and dianhydride are provided in a solution within which a low molecular weight polyamic acid is formed. The solution is dried. The polyamic acid used is cured to a low molecular weight polyimide. The polyimide is redisolved, redryed and recured enough times to build up the molecular weight to a useful level. The method is applicable to fabricating other polymers of high molecular weight, such as polyamides, polyesters and polyurethanes.