Hierarchical porous structure contained composite polyimide flm with enhanced dielectric and water resistance properties for dielectric material
writer:Zian He 1, Junwen Xie 1, Ziwei Liao, Yingyi Ma *, Mingyan Zhang, Wenlong Zhang, Hongyan Yue, Xin Gao
keywords:Hierarchical porous structure, Composite PI flm, Dielectric property, Water resistance, Durability
source:期刊
Issue time:2021年
Low-dielectric-constant materials are in great demands to satisfy the requirements in microelectronics. In this study, polyhedral oligomeric silsesquioxanes (POSS) contained hierarchical porous structure, which was prepared by the self-assembly of water droplets, was used as a coating for ?at polyimide (PI) flm. Evident declines were found in dielectric constant and water uptake upon the introduction of the hierarchical porous coating due to the existence of ?uorine-containing groups, POSS and the hierarchical porous structure. In addition, almost undamaged mechanical properties were shown when the dielectric and water resistance properties were optimized because the hierarchical porous structure was used as a coating but not the bulk of the PI flm. When the content of POSS varies from 10 % to 50 %, low dielectric constants of 2.42–2.75 and low water uptakes of 0.60 %– 0.67 %, with 22 %– 27.63 % and 75.96 %–78.43 % of reductions were obtained, compared to 3.36 of dielectric constant and 2.80 % of water uptake for ?at PI flm. More importantly, the stability of dielectric properties in humid environment was verifed by only 2.94 %–4.83 % of increase in dielectric constant after exposing to high humidity for more than 25 h, compared to 9.43 % of increase for ?at PI flm. The present study provides a versatile method for the preparation of low-dielectric-constant polymer materials with comprehansive properties.