Synthesis Of Aromatic Benzoxazole Polymers For High T-G, Low Dielectric Properties

Next generation microelectronic packaging requirements are driving the need to produce increasingly lower dielectric constant materials while maintaining high thermal stability and ease of processing. Important material requirements for these applications include low dielectric constant, high thermal, thermooxidative and dimensional stabilities, T-g above 350degreesC, low thermal expansion coefficient and low moisture uptake. Required dielectric constants will be between 2.0-2.4, with a progressive need for a figure of merit below 2.0. Our research efforts have focused on the synthesis and characterization of new polymer compositions with a view to meeting the objectives of imparting high thermal stability (degradation temperatures substantially higher than 350degreesC), low moisture uptake (less than 1%), solubility for processing in common organic solvents, as well as obtaining dielectric constants less than 2.5 and low thermal expansion coefficients. The logical extension of such an approach has recently resulted in some unique post-polymerization chemistry involving intramolecular rearrangement and crosslinking of the candidate polymeric materials to provide resistance to chemicals encountered during microelectronic packaging.