Facile Strategy for Intrinsic Low-k Dielectric Polymers: Molecular Design Based on Secondary Relaxation Behavior

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

The development of microelectronics and large-scale intelligence nowadays promotes the integration, miniaturization, and multifunctionality of electronic and devices but also leads to the increment of signal transmission delays, crosstalk, and energy consumption. The exploitation of materials with low permittivity (low-k) is crucial for realizing innovations in microelectronics. However, due to the high permittivity of conventional interlayer dielectric material (k ∼ 4.0), it is difficult to meet the demands of current microelectronic technology development (k < 3.0). Organic dielectric materials have attracted much attention because of their relatively low permittivity owing to their low material density and low single bond polarization. Polyimide (PI) exhibits better application potential based on its well permittivity tunability (k = 1.1-3.2), high thermal stability (>500 °C), and mechanical property (modulus of elasticity up to 3.0-4.0 GPa). In this review, based on the synergistic relationship of dielectric parameters of materials, the development of nearly 20 years on low-k PI is thoroughly summarized. Moreover, process strategies for modifying low-k PI at the molecular level, multiphase recombination, and interface engineering are discussed exhaustively. The industrial application, technological challenges, and future development of low-k PI are also analyzed, which will provide meaningful guidance for the design and practical application of multifunctional low-k materials.

Facile strategy for intrinsic low-κ dielectric polymers: molecular design based on space charge conservation

The growing need for high-power and compact-size microelectronic integrated circuits (ICs) in modern microelectronic industries and 5G communication systems demands low dielectric constant (κ) polymer dielectrics with excellent temperature capability, mechanical property and processability. However, conventional molecular design strategies often face difficulties of a trade-off between optimizing the dielectric performance of polymers and maintaining the aforementioned properties. Herein, we present an innovative and facile strategy that utilizes the space charge distribution characteristics of the target co-monomer to solve this trade-off. Based on this design strategy, a novel polyaryl ether ketone (PAEK) with two different charge distribution units (BAF and SBI) was designed and synthesized. Both the experimental results and computational simulations confirm that these two components serve to weaken the polarization of molecular chains in the electric field, induce higher molecular chain packing density and fewer weaknesses, and synchronously regulate the κ, dielectric loss (tan δ), thermal and mechanical properties and processability by generating a strong inter-chain electrostatic interaction. The resultant copolymer, PAEK-4F6S, exhibits exceptional low κ and tan δ values of 1.98 and 0.0024 at 1 MHz, respectively, and these values remain stable over a broad frequency (1-106 Hz, 8.2-12.4 GHz) and temperature range (30-150 °C). Furthermore, the resultant copolymer demonstrates excellent thermal stability and mechanical properties, with a glass transition temperature (Tg) of 195 °C, 5 wt% decomposition temperature (Td5%) of 498 °C under N2, tensile strength of 63.5 MPa and tensile modulus of 1011.2 MPa, respectively. The synthesis procedure of these resultant copolymers is facile, and they are found to have favorable solution and melt processing properties, making them suitable for processing and scalable production. More importantly, this design strategy is beneficial for lowering the κ and tan δ values, and simultaneously enhancing the comprehensive performances of the objective polymers, which provides a completely novel and facile approach for the design and fabrication of high performance low-κ polymers suitable for the needs of microelectronics and communication fields.

Recent advancements in bio-based dielectric and piezoelectric polymers and their biomedical applications

The advent of polymer-based dielectrics marked a significant breakthrough in dielectric materials. However, despite their many advantages, they pose serious environmental threats. Therefore, in recent years, there has been growing interest in bio-based polymers as a sustainable alternative to traditional petroleum-based polymers. Their renewable nature and reduced environmental impact can fulfil the rising demand for eco-friendly substitutes. Beyond their ecological benefits, bio-based polymers also possess distinctive electrical properties that make them extremely attractive in a variety of applications. Considering these, herein, we present recent advancements in bio-based dielectric polymers and nanocomposites. First, the fundamental concepts of dielectric and polymer-based dielectric materials are covered. Then, we will delve into the discussion of recent advancements in the dielectric properties and thermal stability of bio-based polymers, including polylactic acid, polyhydroxyalkanoates, polybutylene succinate, starch, cellulose, chitosan, chitins, and alginates, and their nanocomposites. Other novel bio-based dielectric polymers and their distinct dielectric characteristics have also been pointed out. In an additional section, the piezoelectric properties of these polymers and their recent biomedical applications have been highlighted and discussed thoroughly. In conclusion, this paper thoroughly discusses the recent advances in bio-based dielectric polymers and their potential to revolutionize the biomedical industry while cultivating a more sustainable and greener future.

Polyimide Films Based on β-Cyclodextrin Polyrotaxane with Low Dielectric and Excellent Comprehensive Performance

In order to prepare polyimide (PI) films with a low dielectric constant and excellent comprehensive performance, a two-step method was employed in this study to integrate β-cyclodextrin into a semi-aromatic fluorine-containing polyimide ternary system. By introducing trifluoromethyl groups to reduce the dielectric constant, the dielectric constant was further reduced to 2.55 at 10 MHz. Simultaneously, the film exhibited noteworthy thermal stability (a glass transition temperature exceeding 300 °C) and a high coefficient of thermal expansion. The material also demonstrated outstanding mechanical properties, boasting a strength of 122 MPa and a modulus of 2.2 GPa, along with high optical transparency (transmittance reaching up to 89% at 450 nm). Moreover, the inherent high transparency of colorless polyimide (CPI) combined with good stretchability contributed to the attainment of a low dielectric constant. This strategic approach not only opens up new opportunities for novel electroactive polymers but also holds potential applications in flexible displays, circuit printing, and chip packaging.

Modeling the Effect of Material Viscoelasticity on the Dielectric Permittivity of Deformed Elastomers

Elastomers, as a typical category of soft dielectrics, have shown great potential for developing stretchable electronics and soft transducers. However, the performance of dielectric elastomers (DEs) is susceptible to the dielectric permittivity of the material, whether as insulators or actuators. On the other hand, experiments suggest that the material viscoelasticity significantly influences the dielectric permittivity of DEs. Based on the theory of finite-deformation viscoelasticity, this work adopts the Brillouin function to develop a modeling framework to examine the effect of material viscoelasticity on the dielectric permittivity for the first time. A comparison of the data fitting results between the models with and without consideration of the material viscoelasticity is presented. Simulation results also reveal that the viscous network of the elastomer exerts a mitigation effect on the decrease in the dielectric permittivity when the material is deformed. Furthermore, it is found that the loading rate is a key parameter that strongly affects the dielectric permittivity, mainly through the inelastic deformation.

Engineering the Dielectric Constants of Polymers: From Molecular to Mesoscopic Scales

Polymers are essential components of modern-day materials and are widely used in various fields. The dielectric constant, a key physical parameter, plays a fundamental role in the light-, electricity-, and magnetism-related applications of polymers, such as dielectric and electrical insulation, battery and photovoltaic fabrication, sensing and electrical contact, and signal transmission and communication. Over the past few decades, numerous efforts have been devoted to engineering the intrinsic dielectric constant of polymers, particularly by tailoring the induced and orientational polarization modes and ferroelectric domain engineering. Investigations into these methods have guided the rational design and on-demand preparation of polymers with desired dielectric constants. This review article exhaustively summarizes the dielectric constant engineering of polymers from molecular to mesoscopic scales, with emphasis on application-driven design and on-demand polymer synthesis rooted in polymer chemistry principles. Additionally, it explores the key polymer applications that can benefit from dielectric constant regulation and outlines the future prospects of this field.

The Influence of Large Pendent Groups on Chain Anisotropy and Electrical Energy Loss of Polyimides at High Frequency through All-Atomic Molecular Simulation

Polyimide is a potential material for high-performance printed circuit boards because of its chemical stability and excellent thermal and mechanical properties. Flexible printed circuit boards must have a low static dielectric constant and dielectric loss to reduce signal loss in high-speed communication devices. Engineering the molecular structure of polyimides with large pendant groups is a strategy to reduce their dielectric constant. However, there is no systematic study on how the large pendant groups influence electrical energy loss. We integrated all-atomic molecular dynamics and semi-empirical quantum mechanical calculations to examine the influence of pendant groups on polymer chain anisotropy and electrical energy loss at high frequencies. We analyzed the radius of gyration, relative shape anisotropy, dipole moment, and degree of polarization of the selected polyimides (TPAHF, TmBPHF, TpBPHF, MPDA, TriPMPDA, m-PDA, and m-TFPDA). The simulation results show that anisotropy perpendicular to chain direction and local chain rigidity correlate to electrical energy loss rather than dipole moment magnitudes. Polyimides with anisotropic pendant groups and significant local chain rigidity reduce electrical energy loss. The degree of polarization correlated well with the dielectric loss with a moderate computational cost, and difficulties in directly calculating the dielectric loss were circumvented.

Comb Polybutadiene with Long Polystyrene Side Chains: A Solution for Tunable Flowability and Enhancing Dielectric Properties in High-Frequency Printed Board Adhesive Films

Liquid high-vinyl polybutadiene (PB) possessed excellent dielectric properties, rendering them suitable candidates for adhesive films of high-frequency printed boards. However, their inherent low molecular weights resulted in chain slippage and overflow during processing, thereby diminishing the performance of the adhesive films. To address this challenge, we synthesized comb PB with long polystyrene side chains via reversible addition-fragmentation chain transfer (RAFT) polymerization, effectively immobilizing the PB backbone and restricting relative chain slippage. Controlling the length and number of "comb teeth" (styrene side chains) efficiently regulated the flowability of comb PB, achieving distinct flow states. Simultaneously, molecular dynamics simulations revealed that the elongated and inflexible polystyrene side chains of comb PB could create minuscule cavities, which impeded close packing of molecules and led to low dielectric constants (2.39/2.01, 1 MHz/10 GHz) and ultralow dielectric losses (0.0071/0.0016, 1 MHz/10 GHz). Furthermore, a series of printed circuit boards were fabricated using a comb PB adhesive film, and the signal loss was significantly reduced to 48.8% (19 GHz) in comparison with a commercial epoxy adhesive. This study demonstrated the potential of comb PB with polystyrene side chains to achieve desirable flow and dielectric properties by introducing tangles, large volume potential resistance, and microporosity compared with block structures.

Design and Synthesis of Low Dielectric Poly(aryl ether ketone) from Incorporation Bulky Fluorene Groups and Regular Hydroquinone Structure

To decrease the dipole polarization rate and reduce the dielectric constant of poly(aryl ether ketone) (PAEK) resin, 1,4-di(4-fluorobenzoyl) cyclohexane (DFBCH), a weakly polarizing cyclohexane-based monomer, was designed and synthesized as the primary reactant. The bulky fluorene group was incorporated to increase the free volume of the resin, further reducing the dielectric constant. Additionally, hydroquinone with a symmetric and regular structure was utilized to enhance the molecular chain's regularity and reduce dipole relaxation, further lowering the resin's dielectric constant and dielectric loss. The PFQEKs series resins exhibited excellent thermal stability with glass transition temperature (Tg) ranging from 222 to 239 °C and 5% weight loss (Td5%) ranging from 458 to 463 °C, with different monomer ratios. As the hydroquinone content increased, the dielectric constant (Dk) and dielectric loss (Df) of the resin decreased significantly, with Dk ranging from 2.92 to 2.77 and Df ranging from 0.011 to 0.008 at 10 GHz.

Optimization of Alkyl Side Chain Length in Polyimide for Gate Dielectrics to Achieve High Mobility and Outstanding Operational Stability in Organic Transistors

Alkyl chain modification strategies in both organic semiconductors and inorganic dielectrics play a crucial role in improving the performance of organic thin-film transistors (OTFTs). Polyimide (PI) and its derivatives have received extensive attention as dielectrics for application in OTFTs because of flexibility, high-temperature resistance, and low cost. However, low-temperature solution processing PI-based gate dielectric for flexible OTFTs with high mobility, low operating voltage, and high operational stability remains an enormous challenge. Furthermore, even though di-n-decyldinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (C₁₀-DNTT) is known to have very high mobility as an air-stable and high-performance organic semiconductor, the C₁₀-DNTT-based TFTs on the PI gate dielectrics still showed relatively low mobility. Here, inspired by alkyl side chain engineering, we design and synthesize a series of PI materials with different alkyl side chain lengths and systematically investigate the PI surface properties and the evolution of organic semiconductor morphology deposited on PI surfaces during the variation of alkyl side chain lengths. It is found that the alkyl side chain length has a critical influence on the PI surface properties, as well as the grain size and molecular orientation of semiconductors. Good field-effect characteristics are obtained with high mobilities (up to 1.05 and 5.22 cm²/Vs, which are some of the best values reported to date), relatively low operating voltage, hysteresis-free behavior, and high operational stability in OTFTs. These results suggest that the strategy of optimizing alkyl side-chain lengths opens up a new research avenue for tuning semiconductor growth to enable high mobility and outstanding operational stability of PI-based OTFTs.

A Novel Diamine Containing Ester and Diphenylethane Groups for Colorless Polyimide with a Low Dielectric Constant and Low Water Absorption

In this study, a novel diamine monomer containing ester and phenyl moieties, 1,2-diphenylethane-1,2-diyl bis(4-aminobenzoate) (1,2-DPEDBA), was synthesized through a three-step reaction. Using this diamine, a novel polyimide (PI) film was prepared with 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6-FDA) as a counter dianhydride through a typical two-step chemical imidization. For comparison, poly(pyromellitic dianhydride-co-4,4'-oxydianiline) (PMDA-ODA PI) was also synthesized via thermal imidization. The resulting 6-FDA-DPEDBA PI film was not only soluble in common polar solvents with high boiling points, such as N,N-dimethylacetamide (DMAc) and N,N-dimethylformamide (DMF), but also soluble in common low-boiling-point polar solvents, such as chloroform (CHCl₃) and dichloromethane (CH₂Cl₂), at room temperature. The resulting novel PI showed a 5% weight loss temperature (T⁵_d) at 360 °C under a nitrogen atmosphere. The resulting PI film was colorless and transparent with a transmittance of 87.1% in the visible light region ranging from 400 to 760 nm. The water absorption of the novel PI film was of 1.78%. The PI film also possessed a good moisture barrier and hydrophobicity. Furthermore, the resulting PI film displayed a low dielectric constant of 2.17 at 10⁶ Hz at room temperature. In conclusion, the novel PI film exhibited much better optical transparency, lower moisture absorption, and a lower dielectric constant as well as better solubility than the PMDA-ODA PI film, which is insoluble in any solvent, although its thermal stability is not better than that of PMDA-ODA PI.

Tetrafluorophenylene-Containing Vinylbenzyl Ether-Terminated Oligo(2,6-dimethyl-1,4-phenylene ether) with Better Thermal, Dielectric, and Flame-Retardant Properties for Application in High-Frequency Communication

In an integrated circuit, signal propagation loss is proportional to the frequency, dissipation factor (D _f), and square root of dielectric constant (D _k). The loss becomes obvious as we move to high-frequency communication. Therefore, a polymer having low D _k and D _f is critical for copper-clad laminates at higher frequencies. For this purpose, a 4-vinylbenzyl ether phenoxy-2,3,5,6-tetrafluorophenylene-terminated OPE (VT-OPE) resin was synthesized and its properties were compared with the thermoset of commercial OPE-2St resin. The thermoset of VT-OPE shows a higher T _g (242 vs 229 °C), a relatively high cross-linking density (1.59 vs 1.41 mmole cm^-3), a lower coefficient of thermal expansion (55 vs 76 ppm/°C), better dielectric characteristic at 10 GHz (D _k values of 2.58 vs 2.75, D _f values of 0.005 vs 0.006), lower water absorption (0.135 vs 0.312 wt %), and better flame retardancy (UL-94 VTM-0 vs VTM-1 with dropping seriously) than the thermoset of OPE-2St. To verify the practicability of VT-OPE for copper-clad laminate, a laboratory process was also performed to prepare a copper-clad laminate, which shows a high peeling strength with copper foil (5.5 lb/in), high thermal reliability with a solder dipping test at 288 °C (>600 s), and the time for delamination of the laminate in thermal mechanical analysis (TMA) at 288 °C is over 60 min.

Facile Strategy for Preparing a Rosin-Based Low-k Material: Molecular Design of Free Volume

Low-k dielectrics are urgently needed in modern integrated circuits. The introduction of free volume instead of porous structures has become a powerful strategy to reduce the k value. According to this strategy, the biomass resource rosin-containing hydrogenated phenanthrene ring was introduced into benzocyclobutene (BCB) resin to reduce the k value; then a rosin-based BCB monomer was successfully synthesized. Meanwhile, the BCB monomer without a rosin skeleton was prepared. After converting the monomers into thermo-crosslinked materials, notably that the rosin skeleton has a great influence on the free volume and k value of the material. The fractional free volume and k value of the former are 26% and 2.44, respectively, and those of the latter are 14% and 2.84, respectively. In addition, the distances between molecular chains and the density of the former are 0.60 nm and 1.06 g cm^-3, respectively; those of the latter are 0.56 nm and 1.28 g cm^-3, respectively. These data show that introducing hydrogenated phenanthrene rings occupies part of the space and hinders the packing of molecular chains, which increases the distance between molecular chains and reduces the density of the polymer, resulting in an increasing free volume and a reducing k value. Notably that introducing hydrogenated phenanthrene rings cannot affect other properties of the material. Therefore, this research indicates that introducing rosin skeletons can prepare high-performance materials, which provide some promising low-k materials for the development of electronics and microelectronics.

Research progress of low dielectric constant polymer materials

The advent of high frequency communication era presents new challenges for further development of dielectric polymer materials. In the field of communication, efficient signal transmission is critical. The lower the dielectric constant of the dielectric material used, the lower the signal delay and the higher the signal fidelity. The preparation of polymer materials with low dielectric constant or reduce the dielectric constant of polymer materials becomes a key research topic. Summarizing past progress and providing perspective, this paper primarily discusses the intrinsic low dielectric polymers, fluorine doped low dielectric polymers, and microporous low dielectric polymers, while predicting the research trend of low dielectric materials.

Dual cross-linking strategy to prepare fluorine-containing poly(arylene ether nitrile) films with a low dielectric constant and ultra-low water uptake

Dual cross-linked networks based on fluorine-containing poly(arylene ether nitrile) were constructed by a simple thermal treatment for obtaining flexible low-dielectric materials with excellent comprehensive performance.

Reduced coefficient of linear thermal expansion for colorless and transparent polyimide by introducing rigid-rod amide units: synthesis and properties

Polyimide films with high optical transparency and dimensional stability and low linear thermal expansion were synthesized by introducing rigid-rod amide units.

Perfluorocyclobutyl-containing transparent polyimides with low dielectric constant and low dielectric loss

The combination of loose chain packing and high fluoro content endows PFCB-containing polyimides with excellent optical transparency and dielectric properties.

Cure kinetics and properties of high-performance epoxy thermosets cured with active ester-terminated poly (aryl ether ketone)

Benzene-1,3,5-triyl tribenzoate (TBB), both 3,5-bis(benzoyloxy)benzoate-terminated poly (aryl ether ketone) oligomers (BPAPK and TMPK), containing active ester (Ph−O−(C=O)− structure), were prepared and served as curing agents for dicyclopentadiene novoalc epoxy (DCPD). The curing kinetics and properties of three epoxy thermosets were systematically investigated. The model reaction of TBB and glycidyl phenyl ether was designed to understand the curing mechanism of oxirane ring with active ester. TMPK/DCPD displays the lowest reaction activation energy, which is the result of the combined influence of free volume and diffusion. In addition, TMPK/DCPD has the highest Tg value (218°C), which enhances 34.6% and 42.5% compared with BPAPK/DCPD and TBB/DCPD, respectively. Meanwhile, TMPK/DCPD also shows superior dielectric and water resistance properties due to no secondary alcohol generated after curing and hydrophobic tetramethyl-substituted biphenyl structure. Herein, TMPK/DCPD as high-performance epoxy thermosets has potential applications in electronic packaging fields.

Intrinsic high-k–low-loss dielectric polyimides containing ortho-position aromatic nitrile moieties: reconsideration on Clausius–Mossotti equation

Intrinsic high-k–low-loss dielectric polyimides containing ortho-position aromatic nitrile moieties were synthesized. 2CN-BTDA shows a D_k of 4.80, D_f of 1.57 × 10⁻³ at 1 kHz (25 °C), E_B of 219.4 kV mm⁻¹ with energy density of 1.023 J cm⁻³ and T_g of 325 °C.

Preparation and Characterization of Semi-alicyclic Polyimides Containing Trifluoromethyl Groups for Optoelectronic Application

Transparent polyimides (PI) films with outstanding overall performance are attractive for next generation optoelectronic and microelectronic applications. Semi-alicyclic PIs derived from alicyclic dianhydrides and aromatic diamines have proved effective to prepare transparent PIs with high transmittance. To optimize the combined properties of semi-alicyclic PIs, incorporating bulky trifluoromethyl groups into the backbones is regarded as a powerful tool. However, the lack of fundamental understanding of structure–property relationships of fluorinated semi-alicyclic PIs constrains the design and engineering of advanced films for such challenging applications. Herein, a series of semi-alicyclic PIs derived from alicyclic dianhydrides and trifluoromethyl-containing aromatic diamines was synthesized by solution polycondensation at high temperature. The effects of alicyclic structures and bulky trifluoromethyl groups on thermal, dielectric and optical properties of PIs were investigated systematically. These PI films had excellent solubility, low water absorption and good mechanical property. They showed high heat resistance with T_g in the range of 294–390 °C. It is noted that tensile strength and thermal stability were greatly affected by the rigid linkages and alicyclic moieties, respectively. These films exhibited obviously low refractive indices and significantly reduced dielectric constants from 2.61 to 2.76, together with low optical birefringence and dielectric anisotropy. Highly transparent films exhibited cutoff wavelength even as low as 298 nm and transmittance at 500 nm over 85%, displaying almost colorless appearance with yellowness index (b*) below 4.2. The remarkable optical improvement should be mainly ascribed to both weak electron-accepting alicyclic units and bulky electron-withdrawing trifluoromethyl or sulfone groups. The present work provides an effective strategy to design molecular structures of optically transparent PIs for a trade-off between solution-processability, low water uptake, good toughness, high heat resistance, low dielectric constant and excellent optical transparency.

Preparation and Properties of Novel Cross-Linked Fluorinated Poly(aryl ether) with Low Dielectric Constant and High Thermal Stability

Fluorinated poly(aryl ether)s (FPAEs) have attracted much attention due to their high thermal stability, excellent mechanical strength, and low dielectric constant. High-molecular-weight fluorinated poly(aryl ether) containing phenylethynyl (FPAE-PE) is successfully synthesized by nucleophilic substitution between 3-ethynylphenol and FPAE. The cross-linked fluorinated poly(aryl ether) (C-FPAE-PE) is prepared by thermal treatment of FPAE-PE at 300 °C. The thermal stability, dynamic thermomechanical property, and dielectric performance of C-FPAE-PE are systematically studied. C-FPAE-PE has excellent heat resistance with 5% weight loss temperature (T_d5% ) at 490 °C in air and high thermomechanical properties with storage modulus retention of 50% at 215 °C. C-FPAE-PE displays low and steady dielectric constant of 2.4 and dielectric loss of 0.004 at 215 °C, exhibiting potential applications in the field of microelectronics, communication technology, and energy storage as high-temperature low dielectric materials.

An effective strategy for the preparation of intrinsic low-k and ultralow-loss dielectric polysiloxanes at high frequency by introducing trifluoromethyl groups into the polymers

Two new CF₃-containing polysiloxanes with low dielectric constant (D_k) and dielectric loss (D_f ) at a high frequency of 5 GHz were reported. The sample with two −CF₃ groups exhibits better dielectric properties with D_k of 2.53 and ultralow D_f of 1.66 × 10⁻³.

Low Dielectric Poly(imide siloxane) Films Enabled by a Well-Defined Disiloxane-Linked Alkyl Diamine

This paper presents an efficient pathway to achieve the dielectric constant as low as 2.48 @ 25 °C, 1 MHz for nonporous poly(imide siloxane) films with mechanical and thermal robustness. A symmetric disiloxane-linked alkyl diamine, bis(aminopropyl)tetramethyldisiloxane (BATMS) with a well-defined molecular formula NH2CH2CH2CH2Si(CH3)2OSi(CH3)2CH2CH2CH2NH2, has been used to controllably reduce the dielectric constant of the polymer films by adjusting the loading of BATMS. The thermal stability of all the polymer films remains robust with T 5 and T 10 no less than 458 and 472 °C, respectively, while the glass-transition temperature decreases with increasing incorporation of flexible disiloxane-alkyl segments into a polymer backbone. There exists a consistent regularity between the thermal, optical, and dielectric properties with the loading amount of BATMS in the polymer films, inferring that the disiloxane-alkyl segments are homogeneously distributed in the polymer backbone. Charge-transfer complex inhibition of polymer films by disiloxane segments has been revealed by an enlarged d-spacing in wide-angle X-ray diffraction spectra and a blue shift in film fluorescence emission spectra. The combined low dielectric constant, robust mechanical and thermal stability, and improved hydrophobicity make the series of BATMS-resulting poly(imide siloxane) films promising candidates for sophisticated flexible microelectronic application.