Achieving Hydrophobic Ultralow Dielectric Constant Polyimide Composites: Combined Efforts of Fluorination and Porous Fillers

Abstract

The advancement of the microelectronics industry necessitates the use of interlayer insulation materials with low dielectric constants and high mechanical properties. In this paper, a new type of copolymerized fluorinated polyimide (PI) is synthesized, and mixed with polyhedral oligomeric silsesquioxane (POSS) functionalized mesoporous silica (MCM-41@POSS). The PI/MCM-41@POSS composites exhibit good hydrophobicity. With the addition of 3 wt% MCM-41@POSS, the PI composite attained an ultralow dielectric constant (k = 1.88) and low dielectric loss (0.01) at 1 MHz, which is attributed to the mesoporous structure of MCM-41 and the restriction of polarization in the bonded region. The decorated POSS effectively prevents the penetration of PI molecular chains into the mesopores of MCM-41. In addition, the PI composites containing 3 wt% of MCM-41@POSS obtain the highest maximum stress of 104.03 MPa with an elongation at break of 13.73%. The hydrophobic PI composites with ultralow-k are expected to be good candidates as interlayer materials in microelectronics devices.

Versatile Landscape of Low-k Polyimide: Theories, Synthesis, Synergistic Properties, and Industrial Integration

“…(b) Comparison of permittivity, tensile strength, and water contact angle of PI, PI/MCM-41, and PI/MAM-41@POSS. Adapted with permission from ref . Copyright 2022 John Wiley and Sons.…”

“…238 Furthermore, a novel MCM-41 composite filler can be prepared by a multiphase composite, which can further reduce the permittivity of PI when it is introduced into the PI matrix. Zhao et al 15 designed a novel composite filler, POSS functionalized mesoporous silica (MCM-41@POSS) as shown in Figure 15a. With the addition of 3 wt % MCM-41@POSS, the PI composites obtained the lowest permittivity (k = 1.88) and dielectric loss (0.01) at 10 6 Hz.…”

“…9,10 Consequently, the design and fabrication of low-k dielectric materials are the key to break the "bottleneck" in the development of electronic power systems. Meanwhile, the exploitation of low-k materials has involved multiple industrial areas, such as communication engineering, 11−13 integrated circuits, 14,15 aerospace, 16,17 and autonomous driving instruments 18 (Figure 1a).…”

“…Due to the increase in voltage and load, the insulation system in transformers has been seriously affected by the difference in permittivity between oil/paper materials, which seriously affects the safety and reliability of equipment in permanent operation. , Consequently, the design and fabrication of low- k dielectric materials are the key to break the “bottleneck” in the development of electronic power systems. Meanwhile, the exploitation of low- k materials has involved multiple industrial areas, such as communication engineering, − integrated circuits, , aerospace, , and autonomous driving instruments (Figure a).…”

Research Advances of Porous Polyimide—Based Composites with Low Dielectric Constant

“…Continued efforts have been devoted to further lowering the dielectric constant by constructing ternary hybrid materials via integrating SiO 2 , POSS and PI due to their synergy effect. Zhao et al [ 81 ] utilized the silane agent 2-(3,4-epoxycyclohexyl)ethyl-trimethoxysilane as a chemical bridge to graft POSS onto the surface of functionalized mesoporous silica MCM-41 and incorporated the POSS functionalized MCM-41 into a quaternary copolymerized FPI synthesized via the polycondensation reaction of 2,2-bis[4-(4-aminophenoxy)phenyl]-hexafluoropropanane, 4,4′-(9-fluorenylidene)dianiline, 4,4-(4,4-Isopropylidenediphenoxy)bis(phthalic anhydride) and (5,5′-biisobenzofuran)-1,1′,3,3′-tetraone. The SiO 2 /POSS/PI composites exhibited good hydrophobicity.…”