Low dielectric constant and highly intrinsic thermal conductivity fluorine‐containing epoxy resins with ordered liquid crystal structures

Abstract

Epoxy resins with a high dielectric constant and low intrinsic thermal conductivity coefficient cannot meet the current application requirements of advanced electronic and electrical equipment. Therefore, novel fluorine‐containing liquid crystal epoxy compounds (TFSAEy) with fluorinated groups, biphenyl units, and flexible alkyl chains are first synthesized via amidation and esterification reactions. Then, 4,4′‐diaminodiphenylmethane (DDM) is used as a curing agent to prepare the corresponding fluorine‐containing liquid crystal epoxy resins. The obtained dielectric constant (ε) and dielectric loss (tan δ) values of TFSAEy/DDM at 1 MHz are 2.54 and 0.025, respectively, which are significantly lower than those of conventional epoxy resins (E‐51/DDM, 3.52 and 0.038). Additionally, the intrinsic thermal conductivity coefficient (λ) of TFSAEy/DDM is 0.36 W/(m·K), 71.4% higher than that of E‐51/DDM (0.21 W/(m·K)). Meanwhile, the corresponding elastic modulus, hardness, glass transition temperature, and heat resistance index of TFSAEy/DDM are 5.73 GPa, 0.35 GPa, 213.5°C, and 188.7°C, respectively, all superior to those of E‐51/DDM (3.68 GPa, 0.27 GPa, 107.2°C, and 174.8°C), presenting potential application in high‐heating electronic component packaging and printed circuit boards.

Polyimide Composites with Fluorinated Graphene and Functionalized Boron Nitride Nanosheets for Heat Dissipation

“…In a previous study, the change of dielectric loss is closely related to the electrical conductivity and the trend of their change is basically the same. The coating of PDA on the surface of the filler results in a rich covalent interface between BNNS and PI, which may form an efficient insulating barrier to hinder the flow of charge carrier, leading to a decrease in the leakage current and reducing the dielectric loss of the composites. , Additionally, the overlap interface can be obtained by the interface interaction of adjacent fillers, reducing the free volume of PI molecular chain, so as to better suppress the interface loss and conductivity loss . In general, tan δ of all of the FG/PDA@BNNS/PI composite films is below 0.014 at 1 MHz in Figure f.…”

“…43,44 Additionally, the overlap interface can be obtained by the interface interaction of adjacent fillers, reducing the free volume of PI molecular chain, so as to better suppress the interface loss and conductivity loss. 45 In general, tan δ of all of the FG/PDA@BNNS/PI composite films is below 0.014 at 1 MHz in Figure 4f. Excellent breakdown resistance is crucial for thermal management materials.…”

Advancements in The Cross-Linking and Morphology of Liquid Crystals

“…Resins containing fluorine atoms in their molecule also have appropriate parameters that ensure the possibility of use in electronics. According to research carried out by Fan et al [66], that kind of resin could be potentially used in electrical circuits prone to excessive heating. LCER can also be used to create fluid functional films Despite their popularity, the production of stimuli-responsive liquid crystal films is a complex process that requires the use of additional conductive layers that allow for control of the display panels.…”

Adhesion Energy-Assisted Low Contact Thermal Resistance Epoxy Resin-Based Composite

“…Epoxy resins have been widely used in electrical packaging, circuit boards, etc., due to their excellent mechanical properties and good processability. − However, with the development of electronic components toward integration, miniaturization, and intelligence, − their increasing heat dissipation requirements pose a big challenge to epoxy resins, which possess low thermal conductivity in the range from 0.1 to 0.5 W/(m·K). The addition of thermal conductive fillers, such as hexagonal boron nitride (h-BN), , boron nitride nanotube, Al 2 O 3 , and carbon materials (carbon nanotube, graphene), has been widely utilized to enhance the thermal conductivity of epoxy resins.…”