A facile method for the preparation of aliphatic main-chain benzoxazine copolymers with high-frequency low dielectric constants

2018 ◽  
Vol 9 (21) ◽  
pp. 2913-2925 ◽  
Author(s):  
Ming Zeng ◽  
Jiangbing Chen ◽  
Qingyu Xu ◽  
Yiwan Huang ◽  
Zijian Feng ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
High Frequency ◽  
Main Chain ◽  
Polymerization Kinetics ◽  
Dielectric Constants ◽  
Low Dielectric

The effects of the reaction solvent on the preparation, polymerization kinetics, and high-frequency dielectric properties of aliphatic main-chain benzoxazine copolymers were investigated.

Synthesis, polymerization kinetics, and high-frequency dielectric properties of novel main-chain benzoxazine copolymers

2018 ◽  
Vol 122 ◽  
pp. 158-166 ◽  
Author(s):  
Qingyu Xu ◽  
Ming Zeng ◽  
Jiangbing Chen ◽  
Shengguo Zeng ◽  
Yiwan Huang ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
High Frequency ◽  
Main Chain ◽  
Polymerization Kinetics

scholarly journals Preparation and Characterization of Electrospun Fluoro-Containing Poly(imide-benzoxazole) Nano-Fibrous Membranes with Low Dielectric Constants and High Thermal Stability

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 537
Author(s):  
Meng-Ge Huangfu ◽  
Deng-Xiong Shen ◽  
Xin-Xin Zhi ◽  
Yan Zhang ◽  
Yan-Jiang Jia ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Dielectric Properties ◽  
High Frequency ◽  
Rapid Development ◽  
Dielectric Constants ◽  
Polymer Materials ◽  
Aromatic Diamines ◽  
Low Dielectric ◽  
Fibrous Membranes ◽  
Poly Imide

The rapid development of advanced high-frequency mobile communication techniques has advanced urgent requirements for polymer materials with high-temperature resistance and good dielectric properties, including low dielectric constants (low-Dk) and low dielectric dissipation factors (low-Df). The relatively poor dielectric properties of common polymer candidates, such as standard polyimides (PIs) greatly limited their application in high-frequency areas. In the current work, benzoxazole units were successfully incorporated into the molecular structures of the fluoro-containing PIs to afford the poly(imide-benzoxazole) (PIBO) nano-fibrous membranes (NFMs) via electrospinning fabrication. First, the PI NFMs were prepared by the electrospinning procedure from organo-soluble PI resins derived from 2,2′-bis(3,4-dicarboxy-phenyl)hexafluoropropane dianhydride (6FDA) and aromatic diamines containing ortho-hydroxy-substituted benzamide units, including 2,2-bis[3-(4-aminobenzamide)-4-hydroxylphenyl]hexafluoropropane (p6FAHP) and 2,2-bis[3-(3-aminobenzamide)-4-hydroxyphenyl]hexafluoropropane (m6FAHP). Then, the PI NFMs were thermally dehydrated at 350 °C in nitrogen to afford the PIBO NFMs. The average fiber diameters (dav) for the PIBO NFMs were 1225 nm for PIBO-1 derived from PI-1 (6FDA-p6FAHP) precursor and 816 nm for PIBO-2 derived from PI-2 (6FDA-m6FAHP). The derived PIBO NFMs showed good thermal stability with the glass transition temperatures (Tgs) over 310 °C and the 5% weight loss temperatures (T5%) higher than 500 °C in nitrogen. The PIBO NFMs showed low dielectric features with the Dk value of 1.64 for PIBO-1 and 1.82 for PIBO-2 at the frequency of 1 MHz, respectively. The Df values were in the range of 0.010~0.018 for the PIBO NFMs.

scholarly journals Sintering, Microstructure, and Dielectric Properties of Copper Borates for High Frequency LTCC Applications

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4017
Author(s):  
Dorota Szwagierczak ◽  
Beata Synkiewicz-Musialska ◽  
Jan Kulawik ◽  
Norbert Pałka
Keyword(s):  
Dielectric Properties ◽  
Dielectric Permittivity ◽  
High Frequency ◽  
Ceramic Materials ◽  
Sintering Behavior ◽  
Terahertz Time Domain Spectroscopy ◽  
Very High Frequency ◽  
X Ray ◽  
Low Dielectric ◽  
Very High

New ceramic materials based on two copper borates, CuB2O4 and Cu3B2O6, were prepared via solid state synthesis and sintering, and characterized as promising candidates for low dielectric permittivity substrates for very high frequency circuits. The sintering behavior, composition, microstructure, and dielectric properties of the ceramics were investigated using a heating microscope, X-ray diffractometry, scanning electron microscopy, energy dispersive spectroscopy, and terahertz time domain spectroscopy. The studies revealed a low dielectric permittivity of 5.1–6.7 and low dielectric loss in the frequency range 0.14–0.7 THz. The copper borate-based materials, owing to a low sintering temperature of 900–960 °C, are suitable for LTCC (low temperature cofired ceramics) applications.

Photosensitive Polyimide having low loss tangent for RF application

2018 ◽  
Vol 2018 (1) ◽  
pp. 000476-000482 ◽  
Author(s):  
Masao Tomikawa ◽  
Hitoshi Araki ◽  
Yohei Kiuchi ◽  
Akira Shimada
Keyword(s):  
Molecular Structure ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
High Frequency ◽  
Low Dielectric Constant ◽  
Low Loss ◽  
Elongation At Break ◽  
Low Dielectric ◽  
The Poor

Abstract Progress of 5G telecommunication and mm radar for autopilot, high frequency operation is required. Insulator materials having low loss at high frequency is desired for the applications. We designed the low dielectric constant, and low dielectric loss materials examined molecular structure of the polyimide and found that permittivity 2.6 at 20GHz, dielectric loss 0.002. Furthermore, in consideration of mechanical properties such as the toughness and adhesion to copper from a point of practical use. Dielectric properties largely turned worse when giving photosensitivity. To overcome the poor dielectric properties, we designed the photosensitive system. After all, we successfully obtained 3.5 of dielectric constant and 0.004 of dielectric loss, and 100% of elongation at break. In addition, we offered a B stage sheet as well as varnish. These materials are applicable to re-distribution layer of FO-WLP, Interposer and other RF applications for microelectronics.

A facile method for the preparation of furfurylamine based benzoxazine resin with high-frequency low dielectric constants and ultra-low dielectric losses

2019 ◽  
Vol 30 (9) ◽  
pp. 8358-8370 ◽  
Author(s):  
Tao Pang ◽  
Ming Zeng ◽  
Zijian Feng ◽  
Jiangbing Chen ◽  
Yiwan Huang ◽  
...  
Keyword(s):  
High Frequency ◽  
Dielectric Constants ◽  
Dielectric Losses ◽  
Low Dielectric

Dielectric Properties of Sol - Gel Silica Glasses

1986 ◽  
Vol 72 ◽  
Author(s):  
G. V. Chandrashekhar ◽  
M. W. Shafer
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Elemental Carbon ◽  
Sol Gel ◽  
Fused Silica ◽  
Dielectric Constants ◽  
Low Dielectric Constant ◽  
Silica Glasses ◽  
Low Dielectric ◽  
Gel Technique

AbstractDielectric properties have been measured for a series of porous and fully densified silica glasses, prepared by the sol-gel technique starting from Si-methoxide or Si-fume. The results for the partially densified glasses do not show any preferred orientation for porosity. When fully densified (˜2.25 gms/cc) without any prior treatment of the gels, they have dielectric constants of ≥ 6.5 and loss factors of 0.002 at 1 MHz, compared to values of 3.8 and <0.001 for commercial fused silica. There is no corresponding anomaly in the d.c. resistivity. Elemental carbon present to the extent of 400–500 ppm is likely to be the main cause for this enhanced dielectric constant. Extensive cleaning of the gels prior to densification to remove this carbon were not completely successful pointing to the difficulty in preparing high purity, low dielectric constant glasses via the organic sol-gel route at least in the bulk form.

Structure and Dielectric Properties of (Gd0.4Sm0.5Yb0.1)2(Zr1-xCex)2O7 Ceramics

2010 ◽  
Vol 105-106 ◽  
pp. 394-397
Author(s):  
Ling Liu ◽  
Qiang Xu ◽  
Fu Chi Wang
Keyword(s):  
Rare Earth ◽  
Dielectric Properties ◽  
Pyrochlore Structure ◽  
Microwave Frequency ◽  
Phase Region ◽  
Dielectric Constants ◽  
Precipitation Method ◽  
Low Dielectric ◽  
Pyrochlore Type ◽  
Co Precipitation

Complex rare-earth zirconates (Gd0.4Sm0.5Yb0.1)2(Zr1-xCex)2O7 (x=0, 0.3, 0.4) powders were synthesized by co-precipitation method. XRD and SEM results revealed that the complex rare-earth zirconates with single pyrochlore structure were prepared and no other phases existed among the grains. The dielectric properties of these compounds were investigated at low and microwave frequencies. It was found that they have intermediate dielectric constants and low dielectric loss in the whole frequency region, and they show the dielectric permittivity with weak frequency dependence. Substituting Zr4+ by Ce4+ leaded to smaller permittivity. Meanwhile, the dielectric contant values increase with increasing in the r(A3+)/r(B4+) value in the pyrochlore-type phase region, which can be explained by the increase in the degree of ordering of oxygen vacancy. This new series of pyrochlore type oxides would be potential candidates for electronic ceramic applications and microwave frequency components.

Quartz fiber cloth-reinforced semi-aromatic thermosetting polyimide composite with high-frequency low dielectric constant

2019 ◽  
Vol 32 (1) ◽  
pp. 91-102 ◽  
Author(s):  
Zhen-he Wang ◽  
Hai-xia Yang ◽  
Shi-yong Yang
Keyword(s):  
High Frequency ◽  
Dielectric Constants ◽  
Molar Ratio ◽  
Mechanical And Thermal Properties ◽  
Quartz Fiber ◽  
Aromatic Diamines ◽  
Low Dielectric ◽  
Dielectric Performance ◽  
Different Temperatures ◽  
Good Heat Resistance

We report a series of semi-aromatic thermosetting polyimide (PI) resins that can be used as matrix for copper-clad laminates for high-frequency applications. The poly(amic ester) (PAE) resins derived from the diester of 1,2,4,5-cyclohexanetetracarboxylic dianhydride, aromatic diamines (the mixture of 2,2′-dimethylbenzidine and 2,2′-bis[4-(4-aminophenoxy) phenyl] propane), and the monoester of nadic anhydride were synthesized by Polymerization of Monomer Reactants (PMR) method. The structure conversion of PAE resins at different temperatures was investigated and the B-stage PI powders prepared by thermally baking the PAE resins at 220°C are nearly fully imidized. The viscosities of the B-stage PI powders and the mechanical and thermal properties of the cured PI resins were optimized by varying the molar ratio of the two diamines. The cured PI resins possess low and steady dielectric constants ( Dk) below 3.0 and dielectric dissipation factors ( Df) of less than 0.01 at high frequency of 1–12 GHz. Furthermore, the quartz fiber cloth-reinforced semi-aromatic thermosetting PI composites (QF/PI) exhibit excellent dielectric performance, good heat resistance, and mechanical properties. At a high frequency of 1–12 GHz, the Dk of QF/PI-4 is stable in the range of 3.16–3.2, and the Df is stable in the range of 0.0026–0.0046. These results suggest the potential of the semi-aromatic QF/PI for use in high-frequency IC boards.

Preparation of the copper-based polyoxometalate/polyurethane composites and their dielectric properties

2019 ◽  
Vol 28 (7) ◽  
pp. 473-483 ◽  
Author(s):  
İlhan Küçük ◽  
Sema Vural ◽  
Nilüfer Kıvılcım ◽  
İbrahim Adıgüzel ◽  
Süleyman Köytepe ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Metal Ion ◽  
In Situ Polymerization ◽  
Synthesis Method ◽  
Dielectric Constants ◽  
Morphological Properties ◽  
Polymerization Process ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Low Dielectric

The aim of this study is synthesis of polyurethane (PU) composites from 4,4′-methylenebis(cyclohexyl isocyanate), 1,2-ethanediol and different amounts of copper-based polyoxometalate (Cu-POM) and investigation of their dielectric properties. Firstly, Cu-POM structure as reinforcement was synthesized with ammonium heptamolybdate and Cu metal ion salt by a hydrothermal synthesis method. Then, Cu-POM-PU composites were prepared by in situ polymerization process. The prepared Cu-POM-PU composites were characterized by means of various techniques for their structure, morphology and thermal behaviour. The chemical structure, surface and morphological properties of the obtained composites were studied by Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) techniques. Thermal properties of these Cu-POM-PU composites were determined by thermogravimetric analysis, differential thermal analysis and differential scanning calorimetry analysis techniques. Dielectric properties of the Cu-POM-PU composites were also determined. The dielectric measured results showed that the dielectric constants decreased with the increase of the Cu-POMs content. The Cu-POM-PU composites showed relatively low dielectric constant compared to pure PUs.

Sign in / Sign up

Export Citation Format

Share Document