Fluorinated graphene/polyimide nanocomposites for advanced electronic packaging applications

Low dielectric constant and low dissipation factor, superior hydrophobicity, excellent thermal and mechanical property, and good optical performance are desired for advanced electronic packaging of fan-out wafer level package (FO-WLP). An effective approach was introduced to fabricate novel fluorinated graphene/polyimide(FG/PI) nanocomposite films in this paper. FG nanosheets exhibit excellent dispersion in the PI matrix due to their high surface area with some oxygen-containing functional groups, and individual graphitized planar structure. Besides, the effects of the addition of FG on the dielectric, optical, mechanical, thermal properties as well as the hydrophobicity of the films are investigated with controlled amounts of FG. The dielectric constant and loss can be as low as 2.64 (at 10(6) Hz) and 0.00176 for PI-0.5wt% FG. And with the increase of the loading of FG, the thermal stability (T-5= 514 degrees C) and mechanical property (tensile modulus = 2.11GPa, tensile strength = 93.23 MPa, elongation at break = 11.60%) has been improved successfully. Besides, the contact angles have been increased from 83 degrees to 92 degrees showing a superior hydrophobicity which is essential for the FO-WLP. Moreover, the incorporation of FG also proved excellent optical performance of 88% transmittance at 550 nm. Therefore, with the excellent comprehensive performance, the as-prepared FG/PI films possess widespread applications in the microelectronics especially in FO-WLP.