A Fluorinated Thermocrosslinkable Organosiloxane: A New Low<i>‐k</i> Material at High Frequency with Low Water Uptake
Fengping Liu, Xingrong Chen, Jiaren Hou, Jing Sun, Qiang Fang
Abstract
Abstract In order to obtain low ‐k material with good comprehensive properties, a trifluoromethyl‐containing organosiloxane with thermocrosslinkable vinyl and benzocyclobutene groups is designed and synthesized through the Piers–Rubinsztajn reaction. After treating at high temperature, the organosiloxane changed to form a cross‐linked polysiloxane (called as c‐FSi‐BCB). c‐FSi‐BCB exhibits good dielectric properties with dielectric constant ( D k ) of 2.60 and dielectric loss ( D f ) of 1.49 × 10 −3 at a high frequency of 5 GHz. Importantly, c‐FSi‐BCB maintains such good dielectric properties and exhibits low water uptake of below 0.076%, even after immersing it in boiling water for 96 h. c‐FSi‐BCB also displays good thermostability with a 5% weight loss temperature ( T 5d ) of 453 °C. These data indicate that this fluorinated organosiloxane is suitable as the matrix resin for the fabrication of devices used in 5G communication.