Enhanced thermal conductivity of polyimide composite film filled with hybrid fillers

Abstract

In this article, the polyimide (PI) composite films with synergistically improving thermal conductivity were prepared by adding a few graphene nanoplatelets (GNP) and various hexagonal boron nitride (h-BN) contents into the PI matrix. The thermal conductivity of PI composite film with 1 wt% GNP and 30 wt% h-BN content was 1.21 W(m·k)− 1, which was higher than that of the PI composite film with 30 wt% h-BN content (0.45 W(m·k)− 1), the synergistic efficiency of GNP under various h-BN content (10 wt%, 20 wt%, and 30 wt%) were 1.70, 2.71, and 3.09, respectively. And it was found that the increased h-BN content can suppress the dielectric properties caused by GNP in the matrix. The dielectric permittivity and dielectric loss tangent of 1 wt% GNP/PI composite film were 10.69, 0.661 at 103 Hz, respectively, and that of the 30 wt% h-BN + GNP/PI composite film were 4.29 and 0.1367, respectively. Moreover, the mechanical properties of the PI composite film were suitable for practical applications. And the heat resistance index and the residual rate at 700°C of PI composite film increased to 326.8°C, 74.43%, respectively, and these of PI film were 292.6°C and 59.26%. Thus, it may provide a reference value for applying the filler hybridization/PI film in the electronic packaging materials.

Preparation and properties of branch‐leaf‐like polyimide composite films with high thermal conductivity and low dielectric loss

“…Li et al used graphene nanosheets (GNP) and boron nitride to reinforce polyimide. 45 The polyimide composite film had a thermal conductivity of 1.21 W/mK when filled with 1 wt% GNP and 30 wt% BN filler, while the dielectric constant was 4.29 and the dielectric loss was 0.1367. The addition of the thermally conductive filler improved the thermal conductivity of the material, mechanical properties and thermal stability performance, but the majority of the composite material filling makes the dielectric properties of the material to decrease, especially the dielectric loss.…”

“…The polyimide composite film had a thermal conductivity of 11.203 W/mK when filled with 1 wt% GO and 20 wt% BN filler, while the dielectric constant exceeded 7, the dielectric loss exceeded 0.015, and the material also maintained excellent mechanical properties and thermal stability. Li et al used graphene nanosheets (GNP) and boron nitride to reinforce polyimide 45 . The polyimide composite film had a thermal conductivity of 1.21 W/mK when filled with 1 wt% GNP and 30 wt% BN filler, while the dielectric constant was 4.29 and the dielectric loss was 0.1367.…”

Crosslinked polyimides with bulky side-group polyhedral silsesquioxanes: Towards lower dielectric constant and better mechanical property

“…In order to minimize signal transmission crosstalk, interconnection resistance-capacitance delay in communication, the dielectric constant and dielectric loss of the dielectric need to be reduced as much as possible. 3 As a common engineering plastic, polyimide (PI) is widely used in gas separation, [4][5][6] electromagnetic shielding and absorbing, 7,8 and thermal conductivity materials [9][10][11] due to its excellent mechanical properties and corrosion resistance. However, since the dielectric constant of polyimides is around 3.2, which is not suitable for the current low dielectric constant requirement, plenty of methods are used to modify polyimides to make its dielectric constant meet the low dielectric constant requirement (k < 3.0).…”

Polyhedral oligosilsesquioxane-modified boron nitride enhances the mechanical properties of polyimide nanocomposites

“…To address this issue, it is generally effective to introduce functional llers into the polymer matrix. 8,9 Common functional llers include graphene, [10][11][12][13] carbon nanotubes, [14][15][16] boron nitride, 17,18 and metal materials. 19 However, graphene, carbon nanotubes, and metallic materials have high conductivity, dielectric constants and dielectric losses, 16,20,21 which are not suitable for electronic insulation materials and seriously hinder the transmission of electronic signals in electronic packaging materials.…”

“…30,31 Currently, many studies describe h-BN composite llers using carbon based nanomaterials such as graphene nanoplatelets, carbon nanotube and MWCNTs in the eld of PI matrix, improving thermal conductivity while minimizing dielectric properties. 8,11,15 However, the poor dispersion and weak interfacial interactions between h-BN and polymer matrix limit the reinforcement effects of h-BN. [32][33][34] A common solution to the abovementioned issue involves the surface modication of h-BN, which enhances the dispersibility and compatibility of the polymer matrix.…”