SiO₂ Hollow Spheres And Graphene Oxide Synergistic Modified Polyimide Composite Films With Low Dielectric Constant

As integrated circuit dimensions continue to decrease, the inter-connect capacitance time delay, line-to-line crosstalk noise and power dissipation have become the main bottlenecks to restrict the development of high speed, high density,low power consumption and multifunction integrated circuit. Using low dielectric constant films as the interlevel dielectrics to replace traditional silicon dioxide to further reduce the dielectric constants of packaging materials and printed circuit board materials is one of the key technologies to solve the problems. Thus, the search for suitable materials with low dielectric constant continues with unrelenting urgency. In order to further reduce their dielectric constants, we have focused on the fabrication of polyimide(PI) composite films by electrospinning and synergistic modified by silica hollow spheres(SHS) and graphene oxide(GO) with low dielectric constant.In this paper, GO were exfoliated by improved method of Hummers, and were modified by ODA. The SHS were synthesized using improved st?ber method. Then the GO/PI, ODA-GO/PI and SHS/ODA-GO/PI composite films were fabricated by dispersing GO and SHS in PI via in situ polymerization. The triple-layer SHS/ODA-GO/PI composite films were fabricated using electrospinning poly. The morphology and structure of GO, ODA-GO, SHS, SHS/ODA-GO were characterized. And composite films were characterized by thermogravimetric analysis, tensile test and dielectic test.The studied on ODA-GO/PI composite films showed that the low dielectric constant was observed for the ODA-GO/PI composite films were 2.35 for the filmsincorporating of 0.3 wt% GO(decreases by 31 % compared to pure PI), and the dielectric loss were decrease slightly. The lamellar thickness of ODA-GO become thinner after modified by ODA. The mechanical strength of ODA-GO/PI composite films reached the maximal. The elongation at break and tensile strength were21.24 %(2.3 times greater than pure PI) and 101.69 MPa(1.3 times greater than pure PI) for the ODA-GO/PI composite films incorporating of 0.7 wt% GO. The thermal stability of the GO/PI composite films had no obvious change compared to that of pure PI.The results of studied on SHS/ODA-GO/PI composite films showed that the combined action of both SHS and ODA-GO reduced the dielectric constant of composite films obviously. The dielectric constants of 1.9 were attained for SHS and ODA-GO concentration of 10 wt% and 0.5 wt% in the triple-layer SHS/ODA-GO/PI composite films(decreases by 44 % compared to pure PI). The thermal stability and mechanical property of the mono layer and triple-layer SHS/ODA-GO/PI composite films had no obvious change compared to that of pure PI.