Benzocyclobutene-functionalized poly(m-phenylene): A novel polymer with low dielectric constant and high thermostability

Thermal Insolubilization of Electrically n-Doped Films Achieved Using 7-Alkoxy-Benzocyclobutene-Substituted Fullerene and Dopant Molecules

Insoluble electrically n-doped fullerene-containing films have been obtained by thermal annealing of a fullerene compound and a 1,3-dimethyl-2,3-dihydro-1H-benzo[d]imidazole n-dopant moiety, both of which are functionalized with a 7-butoxybenzocyclobutene group. The covalent tethering and electrical doping reactions are studied by mass spectrometry as well as electron paramagnetic resonance. Optical absorption spectra on BBCB-N-DMBI-H-doped BBCBP indicate films heated at 150 °C for 10 min are unaffected by immersion for 10 min in ortho-dichlorobenzene. Although films containing a 10 mol % loading of the dopant showed electrical conductivity values of 1.1 × 10^-5 ± 3.4 × 10^-7 S cm^-1 prior to heating, the thermal insolubilization process led to values around two orders-of-magnitude lower. However, the thermal insolubilization also leads to immobilization of the dopant molecule and the corresponding cation, reducing their ability to diffuse into an adjacent layer of a stronger electron acceptor.

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.

Low dielectric resins derived from hyperbranched carbosilane oligmers functionalized by benzocyclobutene groups

Polycarbosilanes have been considered as potential materials used in electronic packaging and circuit boards owing to their excellent low-dielectric performance. In this work, we prepared new hyperbranched carbosilane oligomers (HCBOs) which were functionalized by benzocyclobutene (BCB) groups. HCBOs can be thermally cured to produce transparent (HCBRs) with low dielectric constant and high thermostability.

Preparation and Characterization of Intrinsic Low-κ Polyimide Films

Three fluorinated polyimide (PI-FP, PI-FO and PI-FH) films with low dielectric constants and excellent comprehensive properties were successfully prepared using a polycondensation reaction method by incorporating p-phenylenediamine (PDA), 4-4′-diaminodiphenyl ether (ODA) and 4,4′-(Hexafluoroisopropylidene) bis (p-phenyleneoxy) dianiline (HFPBDA) into 4,4′-(Hexafluoroisopropylidene) diphthalic anhydride (6FDA), respectively. The effects of the diamine monomer structure on optical, dielectric and mechanical properties were investigated. Compared with PDA and ODA, HFPBDA can effectively improve the optical and dielectric properties of PI due to due to its special chain structure. Among the three PI films, PI-FH film presents the best optic transmission (highest transmittance = 90.2%) and highest energy gap (2.69 eV). The dielectric properties of PI-FH film improve the most. The dielectric constant and loss at 10⁴ Hz are reduced to 2.05 and 0.0034 at 10⁴ Hz, respectively, and remain stable up to 250 °C. The mechanical properties decrease in turn for PI-FP, PI-FO and PI-FH films due to the increase in free volume fraction. Nevertheless, PI-FH film still exhibits good mechanical properties with a tensile strength of 88.4 Mpa, a tensile modulus of 2.11 GPa and an elongation at break of 4.1%. The correlation between the dielectric and mechanical properties of PI films and their free volume characteristics is well explained with the help of positron annihilation spectroscopy.

Benzocyclobutene-functionalized hyperbranched polysiloxane for low-k materials with good thermostability

Although hyperbranched polysiloxanes have been extensively studied, they have limited practical applications because of their low glass transition temperatures. In this study, we synthesized benzocyclobutene-functionalized hyperbranched polysiloxane (HB-BCB) via the Piers-Rubinsztajn reaction. The synthesized material was cured and crosslinking occurred at temperatures greater than 200 °C, forming a low-k thermoset resin with high thermostability. The structure of the resin was characterized using nuclear magnetic resonance (NMR) spectroscopy, viz. ¹H NMR and ¹³C NMR spectroscopy. ²⁹Si NMR spectroscopy was used to calculate the degree of branching. Differential scanning calorimetry, dynamic mechanical analysis, and thermogravimetric analysis revealed that the cured resin possesses good high-temperature mechanical properties and exhibits a high thermal decomposition temperature (T_d5 = 512 °C). In addition, the cured resin has a low dielectric constant (k = 2.70 at 1 MHz) and low dissipation factor (2.13 × 10^-3 at 1 MHz). Thus, the prepared resin can function as a low-k material with excellent high-temperature performance. These findings indicate that the performance of crosslinked siloxane is significantly attributed to the introduction of BCB groups and the formation of the highly crosslinked structure.

Biorenewable rosin derived benzocyclobutene resin: a thermosetting material with good hydrophobicity and low dielectric constant

Development of bio-based polymers has been promoted by the growing concerns about the long-term sustainability and negative environmental footprint of petroleum-based polymer materials. A new monomer containing benzocyclobutene and allyl units has been developed by using rosin as the feedstock. The structure of the monomer was characterized by elemental analysis, MS, FT-IR and NMR spectroscopy. The monomer could be converted to the polymer via thermal ring-opening polymerization which was characterized via FT-IR, thermogravimetric analysis (TGA), atom force microscopy (AFM) and so on. The polymer showed good dielectric properties and hydrophobicity with an average dielectric constant of 2.51 in a range of frequencies from 0.1 to 18 MHz and a water contact angle of 106°. In addition, the polymer with other comprehensive performances exhibited a 5% weight loss temperature of 406 °C, a surface roughness (R_a) of 0.658 nm in a 5.0 × 5.0 μm² area, hardness and Young's modulus of 0.283 and 3.542 GPa, and storage modulus of 11.46 GPa at 30 °C. These data suggest that the polymer may have potential application in electronics and microelectronics.

The rosin structure was introduced into benzocyclobutene resin for the first time, and the thermosetting material with good hydrophobicity and low dielectric constant was prepared.

POSS-benzocyclobutene (POSS-BCB) resin

Organic-inorganic hybrid materials with a high thermal stability and a low dielectric constant show great potential in the microelectronics industry. In this work, polyhedral oligomeric silsesquioxane-benzocyclobutenes (POSS-BCBs) were synthesized by a hydrosilylation reaction of octavinyloctasilasesquioxane (OVPOSS) and 4-(1,1-dimethyl-1-hydro)-silyl-benzocyclobutene with H2PtCl6 as a catalyst. The ring-opening reaction of BCB on POSS-BCBs resulted in POSS-BCB resins with a highly cross-linked network structure. This resin exhibited good thermal stability (T5% is 495°C in N2), low dielectric constants (<2.1 at 20 MHz) and low water absorption.

Hydrolysis and condensation of a benzocyclobutene-functionalized precursor for the synthesis of high performance low-K polymers

A new synthetic route involving the hydrolysis and condensation of a BCB precursor for high performance low-K benzocyclobutene-functionalized polymers was developed.

A new fluoropolymer having triazine rings as a dielectric material: synthesis and properties

A novel fluoropolymer having triazine rings and thermo-crosslinkable benzocyclobutene units is prepared by a facile phase transfer catalyzed interfacial polycondensation reaction between a diphenol and a dichloro-s-triazine.

A spiro-centered thermopolymerizable fluorinated macromonomer: synthesis and conversion to the high performance polymer

A new spiro-centered thermopolymerizable fluorinated macromonomer is reported here.

Facile conversion of plant oil (anethole) to a high-performance material

Anethole, a naturally occurring aromatic compound which can be extracted abundantly from plants like star anise, fennel and basil, has been conveniently transformed to a functional monomer in an overall yield of 81% via a two-step procedure.

A new glass-forming molecule having a fluorene skeleton: synthesis and conversion to the polymer with a low dielectric constant, high hydrophobicity and thermostability

A new glass-forming molecule having a fluorene skeleton and thermally cross-linkable trifluorovinyl-ether side chains is reported here.

Benzocyclobutene resin with m-carborane cages and a siloxane backbone: a novel thermosetting material with high thermal stability and shape-memory property

A simple and effective way to synthesize carborane-containing benzocyclobutene resin with excellent performances.

High-performance intrinsic low-k polymer via the synergistic effect of its three units: adamantyl, perfluorocyclobutylidene and benzocyclobutene

Intrinsic highly cross-linked low-k benzocyclobutene polymer functionalized with adamantyl and perfluorocyclobutylidene.

A novel one-pot synthesized organosiloxane: synthesis and conversion to directly thermo-crosslinked polysiloxanes with low dielectric constants and excellent thermostability

A novel organosiloxane containing a thermally cross-linkable benzocyclobutene group was successfully synthesized through a one-pot Grignard reaction procedure.

Propargyl ether-functionalized poly(m-phenylene): a new precursor for the preparation of polymers with high modulus and high Tg

A propargyl ether-functionalized poly(m-phenylene) (PE-PMP) is reported here.