Properties Of Polyhedral Oligomeric Silsesquioxane/Graphene Oxide/Polyimide Composite Films With Low Dielectric Constant

With the developing of intergrated circuit industry in recemt years,the size of intergrated circuit is becoming smaller.Low-dielectric constant film used as interlayer media has great potential to solve the issue.Polyhedral oligomeric silsesquioxane(POSS)is introduced to introduce nanopores into polymer matrix,the dielectric constant of air is 1,which can obviously reduce the dielectric constant of polymer.It can enhance the thermal behavior of the polymer,because POSS consists of inorganic hollow core,which provides good heat resistance,and external organic functional groups,which enhances compatibility with polymer matrix.Our study aimed at using POSS and graphene oxide(GO)as fillers to synthesis polyimide composites in order to obtain a low-dielectric constant films.In this study,4,4'-oxybisbenzenamine(ODA)and pyromellitic dianhydride(PMDA)were used as monomers to synthesis PI films.In situ polymerization was used to prepare POSS/PI composite films by introducing POSS nanofillers and prepare ODA-GO/POSS/PI composite films by introducing ODA modified GO which have low dielectric constant.The morphology and structure of nano fillers and composite films was characterized.The effects of composite films and POSS and GO content was studied.The studies on POSS/PI composite films showed that the dielectric constant of composite films can be reduced by incorporating POSS,and the abtained lowest dilectric constant of composite films is 2.60(1 MHz)by incorporating 2 wt% POSS(decreases by 25.7 % than neat PI),and the dielectric loss was decreased slightly.The thermal properties of POSS/PI were improved.Thermal decomposition temperature of 5 wt% weight loss for composite films was increased for the film with incorporating 2 wt% POSS.A series of studies were adopted to ODA-GO/POSS/PI composite films,the results showed that the introduction of ODA-GO further reduced the dielectric constant of composites.The lowest dielectric constant of films was 2.5(1 MHz)for the film of incorporating 0.5 wt% ODA-GO and 2 wt% POSS(decreased by 26.4 % compared to neat PI).By introducing ODA-GO nanosheets into POSS/PI films,the mechanical properties was obviously improved.The tensile strength and elongation of three-phase composite films are 93.5 MPa and 11.3 % respectively by incorporating 0.5 wt% ODA-GO and 2 wt% POSS.The obtained tensile strength increased by 11.2% compared to neat PI.Elongation at break increased by 18.9 % compared to neat PI.