LOW DIELECTRIC CONSTANT NANOCOMPOSITE FIBERMATS PRODUCED BY ELECTROSPINNING

摘要

Multifunctional nanofibers can be produced by an electrostatic spinning process where a highvoltage is applied between a polymer solution containing functional nanoparticles and a ground plate at adistance. Currently, the process is being optimized by varying process parameters, such as polymer solutionconcentration, electro voltage, collector distance, and nanoparticle volume fraction.In microelectronic applications, low dielectric constant material is actively sought for reducing theresistance-capacitance (RC) time delay of inter-connects and cross talk between metal lines. One ofpromising methods is to introduce porosity into low dielectric constant materials.Ultra-low dielectric constant fibrous film is fabricated from such electrospinning process withPolyacrylonitrile (PAN). High porous film with an average of 83% porosity can be readily obtained. Themeasured dielectric constants show values between 1.4~1.6 compared to the current low dielectric constantmaterial of 2.2. By electrospinning with nanoparticles the dielectric constant is further reduced. The addedfunctional nanoparticles may also have various functional enhancements, such as strength and toughness tomeet the application requirements. Several nanoparticles such as iron oxide, graphite nanoplatelet, andcarbon nanotube are investigating for its applicable functionality.