High dielectric constant and high breakdown strength polyimide <i>via</i> tin complexation of the polyamide acid precursor

Abstract

Polymer dielectrics with ultra-high charge-discharge rates are significant for advanced electrical and electronic systems. Despite the fact that polymers possess high breakdown strength, the low dielectric constant (<i>k</i>) of polymers gives rise to low energy densities. Incorporating metal into polyimides (PI) at the polyamic acid (PAA) precursor stage of the synthetic process is a cheap and versatile way to improve the dielectric constant of the hybrid system while maintaining a high breakdown strength. Here, we explore inclusion of different percentages of Sn as a coordinated complex in a polyimide matrix to achieve metal homogeneity within the dielectric film to boost dielectric constant. Sn-O bonds with high atomic polarizability are intended to enhance the ionic polarization without sacrificing bandgap, a measurable property of the material to assess intrinsic breakdown strength. Enhancements of <i>k</i> from <i>ca.</i> 3.7 to 5.7 were achieved in going from the pure PI film to films containing 10 mol% tin.